RVBXST600Thermosafer

Applicant Declaration QSF27-14-04 Rev 1.4 April 25, 2025 Page 1 of 1 Original Issue: Jan. 4, 2021 SGS North America Inc. 620 Old Peachtree Road SUITE 100 Suwanee, Georgia 30024 United States Applicant Legal Business Name ChoisTechnology Co.,Ltd. Address S-1404, 32, Songdogwahak-ro, Yeonsu-gu, Incheon, South Koreaa FRN 0010388171 Grantee Code RVB FCC ID: RVBXST600 Authorized Contact Name Daeheung Son Contact Phone 82-32-246-3404 Contact Email [email protected] I, the undersigned, certify that I am an authorized signatory for the Applicant and therefore declare; a) in accordance with 47CFR2.911(d), all of the statements herein and the exhibits attached hereto are true and correct to the best of my knowledge and belief. b) in accepting a Grant of Equipment Authorization issued by a TCB, under the authority of the FCC, as a result of the representations made in this application, the Applicant is responsible for: (1) labeling the equipment with the exact FCC ID as specified in this application, (2) compliance statement labeling pursuant to the applicable rules, (3) compliance of the equipment with the applicable technical rules, c) if the Applicant is not the actual manufacturer of the equipment, appropriate arrangements have been made with the manufacturer to ensure that production units of this equipment will continue to comply with the FCC’s technical requirements. d) in accordance with 47 CFR 2.909 and KDB394321, the Applicant has read, understood and agrees to accept that they are the responsible party and agree to abide by their responsibilities as specified under 47 CFR 2.909 and KDB394321. e) in accordance with ISO 17065, FCC KDB641163, FCC KDB610077, KDB394321 and RSP-100, the Applicant has read, understood, accepts and agrees to abide by the post market surveillance requirements. (1) the Applicant understands, accepts and agrees that a sample may be requested for surveillance testing. (2) the Applicant shall make provisions to always have a production sample available upon request by SGS, FCC and/or ISED. (3) the Applicant shall, upon request by SGS, at the Applicant’s expense, provide a production sample of the requested product to SGS, FCC and/or ISED as instructed. The sample shall include all support devices, cables, software, accessories or other hardware or software required for evaluation, review, certification and audit surveillance of products certified by SGS. f) neither the Applicant nor any party to the application is subject to a denial of Federal benefits, that includes FCC benefits, pursuant to Section 5301 of the Anti-Drug Abuse Act of 1988, 21 U.S.C. §862 because of a conviction for possession or distribution of a controlled substance. See 47CFR 1.2002(b) for the definition of a “party” for these purposes. g) the Applicant has read, understood, accepts and agrees to abide by the SGS North America, Inc. terms and conditions as specified in the TCB Application Form 731 (QSF27-14-01). Link to CFRs: https://www.fcc.gov/wireless/bureau-divisions/technologies-systems-and-innovation-division/rules-regulations-title-47 Link to KDBs: https://apps.fcc.gov/oetcf/kdb/index.cfm Link to RSP-100: https://www.ic.gc.ca/eic/site/smt-gst.nsf/eng/sf01130.html Link to the Covered List: Covered List Applicant Signature: Date: 2026/04/23 Print Name: Daeheung Son Title: Director *NOTE: This declaration cannot be signed by an Agent, it shall be signed by an authorized person listed in the FCC database

FCC COVERED LIST DECLARATION LETTER Page 1 of 1 Revision 1.0 SGS North America Inc. 620 Old Peachtree Road SUITE 100 Suwanee, Georgia 30024 United States Applicant Legal Business Name Chois Technology Co.,Ltd. Address S-1404, 32, Songdogwahak-ro, Yeonsu-gu, Incheon, South Korea FRN 0010388171 Grantee Code RVB FCC ID: RVBXST600 Authorized Contact Name Daeheung Son Contact Phone 82-70-5118-5568 Contact Email [email protected] ChoisTechnology Co.,Ltd. (“the applicant”) certifies: - the equipment for which authorization is sought is not “covered” equipment prohibited from receiving an equipment authorization pursuant to section 2.903 of the FCC rules. - as of the date of the filing of the application, the applicant is not identified on the Covered list, established pursuant to §1.50002, as an entity producing “covered” equipment. - the software to be loaded prior to marketing of the equipment identified above is not “covered” software manufactured by any entity including predecessors, successors, parents, subsidiaries, affiliates or any entity which has rebranded or relabeled the software produced by the entity(ies) identified on the “Covered List”. - the device is not capable of storing or running software listed on the covered list and therefore is inherently compliant. NOTE: Justification/evidence explaining how compliance is met must accompany this letter Link to the Covered List: Covered List Applicant Signature: Date: 2026/04/23 Print Name: Daeheung Son Title: Director *NOTE: This declaration cannot be signed by an Agent, it shall be signed by an authorized person listed in the FCC database

iCertifi Control Number - IC2026ASOP12317 Federal Communications Commission Authorization and Evaluation Division 7435 Oakland Mills Road Columbia, MD 21046 USA Date: 23/04/2026 Ref: Attestation Statement Part 2.911(d)(7) Filing FCC ID: RVBXST600 Chois Technology Co., Ltd. certifies that, as of the dates of this application, Americas Compliance Consulting LLC dba iCertifi is our designated U.S. agent for service of process for the above referenced FCC ID. Manufacturer accepts to maintain an agent for no less than two year after the grantee has terminated all marketing and importation or the conclusion of any commission-related proceeding involving the equipment. iCertifi accepts, as of the date of the filing of the application, the obligation of the designated U.S. agent for service process for the above referenced FCC ID. Designated U.S. Agent Information: Name: Americas Compliance Consulting LLC dba iCertifi FCC FRN: 0033399411 Address: 5809 US-2, Suite B, Albeni Plaza Priest River, Idaho 83856, United States Contact Person: Paul Preston Tel: +1 (866) 885-4575 Email: [email protected] Sincerely, Chois Technology Co., Ltd.Americas Compliance Consulting LLC dba iCertifi FRN: 0010388171FRN: 0033399411 Daeheung SonPaul Preston [email protected]@icertifi.com +82-70-5118-5568+1 (866) 885-4575 Signature: Signature:

ChoisTechnology Co., Ltd. S-1404, 32, Songdogwahak-ro, Yeonsu-gu, Incheon, South Korea Date : 2026/04/23 Federal Communications Commission Authorization and Evaluation Division 7435 Oakland Mills Road, Columbia, MD 21046 LETTER FOR AUTHORIZATION FCC ID: RVBXST600 To whom it may concern: I, the undersigned, hereby authorize SGS Korea Co., Ltd. and hereafter referred to as SGS Korea, to act on our behalf in all manners relating to application for equipment authorization, including signing of all documents relating to these matters. Any and all acts carried out by SGS Korea Co., Ltd. on our behalf shall have the same effect as acts of our own. I, the undersigned, hereby certify that we are not subject to a denial of federal benefits, that includes FCC benefits, pursuant to Section 5301 of the Anti-Drug Abuse Act of 1988, 21 U.S.C. 853(a). In authorizing SGS Korea as our agent, we still recognize that we are responsible to: a) comply with the relevant provisions of the certification program; b) make all necessary arrangements for the conduct of the evaluation, including provision for examining documentation and access to all areas, records (including internal audit reports) and personnel for the purposes of evaluation (e.g. testing, inspection, assessment, surveillance, reassessment) and resolution of complaints; c) make claims regarding certification only in respect of the scope for which certification has been granted; d) do not use our product certification in such a manner as to bring the Certification Division into disrepute and not make any statement regarding our product certification which the Certification Division may consider misleading or unauthorized; e) upon suspension or cancellation of certification, discontinue use of all advertising matter that contains any reference thereto and return any certification documents as required by the Certification Division; ChoisTechnology Co., Ltd. S-1404, 32, Songdogwahak-ro, Yeonsu-gu, Incheon, South Korea f) use certification only to indicate the products are certified as being in conformity with specified standards; g) endeavor to ensure that no certificate or report nor any part thereof is used in a misleading manner; h) ensure that any reference to our product certification in communication media such as documents, brochures or advertising, complies with the requirements of the Certification Division; i) keep a record of all complaints made known to the us relating to the product’s compliance with requirements of the relevant standard and to make these records available to the Certification Division when requested; j) take appropriate action with respect to such complaints and any deficiencies found in products or services that affect compliance with the requirements for certification; k) document the actions taken. This authorization is valid until further written notice from the applicant. Sincerely Yours Name : Daeheung Son Title : Director Company Name : ChoisTechnology Co., Ltd.

ChoisTechnology Co., Ltd. S-1404, 32, Songdogwahak-ro, Yeonsu-gu, Incheon, South Korea Date : 2026/04/23 Federal Communications Commission Authorization and Evaluation Division 7435 Oakland Mills Road, Columbia, MD 21046 REQUEST FOR CONFIDENTIALITY FCC ID: RVBXST600 Pursuant to Sections 0.457 and 0.459 of the Commission’s Rules (CFR 47), and Section 552 (b) (4) of the Freedom of Information Act, Chois Technology Co.,Ltd hereby requests confidentiality and treatment of certain information accompanying this application. The materials contain trade secrets and proprietary information not customarily released to the public. The public disclosure of these matters might be harmful to the Applicant and provide unjustified benefits to its competitors. We are also hereby request Short-Term Confidentiality for 180 days after the grant as outlined in Public Notice DA 04-1705. This provision will give , Chois Technology Co.,Ltd temporary confidentiality of commercially sensitive information prior to product release. The requested Permanent and Temporary Confidential exhibits are listed as follows: CONFIDENTIAL LIST Permanent 1 Block Diagram 2 Operational Descriptions 3 Schematics Short-Term 4 External Photos 5 Internal Photos 6 Test-Setup Photos 7 User Manual The Applicant understands that pursuant to Rule 0.457, disclosure of this application and all accompanying documentations, where applicable, will not be made public before the date of the Grant for this application. Sincerely Yours Name : Daeheung Son Title : Director Company Name : Chois Technology Co.,Ltd

XST600 FCC LABEL INFORMATION •Due to the small size of the product, the FCC ID and FCC statements will be included in the user manual, and the FCC ID label will be placed on the device packaging. ·Compatible Bluetooth LE ·Smartphone compatible OS iOS: �� or above / Android �.� or above ·or more detailed device compatibility, please scan the QR code on the right or check our website. www.choistec.com “This radio device is not allowed to be used for services related to human safety since it has the possibility of radio interference during operation.” �) Country of Origin : Republic of KOREA �) Warranty Period : � year FCC RF Radiation Exposure Statement: This equipment complies with FCC RF Radiation exposure limits set forth for an uncontrolled environment. This device and its antenna must not be co-located or operating in conjunction with any other antenna or transmitter. FCC ID : RVBXST��� This device complies with part �� of the FCC Rules. Operation is subject to the following two conditions: (�) This device may not cause harmful interference, and (�) this device must accept any interference �) Product Name(Model Name): Thermosafer(XST���) �) Common Name : Clinical Electronic Thermometer �) Item Name: Electronic Thermometer �) Name & Address of Manufacturer: CHOISTECHNOLOGY CO., LTD. / #S-����, Building S, Songdo Technopark IT Center, ��, Songdo gwahak-ro, Yeonsu-gu, Incheon,�����, Korea �) Item License Number: License No. ��-��� �) Intended Use: A device for measuring a patient's body temperature using electrical properties �) Measure site : forehead (Reference body site : oral) �) Operating Mode : Direct Mode �) Serial Number: Indicated on the product ��) Manufacturing Date: separately labeled on product box ��) Performance and Usage Method: Refer to user manual ��) Accuracy(Testlab): ±�.�°F / ±�.��°F ��) Storage Method: Refer to user manual ��) Precautions for Use: Refer to the user manual ��) Package Unit: XST��� �EA, XST��� Probe �EA ��) Other Required Information ➀ Type and Degree of Protection Against Rating: Internally Powered Equipment, Type BF Applied Part ➁ Power Rating, Rated Voltage, and Rated Frequency: CR����(�V,��mAh) Warning (Magnet Interference): This device contains a permanent magnet used for the connection between the main body and the sensor probe. To prevent potential interference with other magnetically susceptible medical devices, such as implanted pacemakers or defibrillators, keep the Thermosafer at least � inches (�� cm) away from such devices at all times. Caution: Federal law restricts this device to sale by or on the order of a licensed healthcare practitioner Continuous Monitoring Temperature & Records Patch Type with Slim Design Long term stability and reliability Real time Temperature Measurement & Alarm Function Operating distance 15m Temperature Data Management �) Store away from water. �) Store at the temperature range of ��°C~��°C and the humidity range of �~��%. �) Store away from dust and moisture. �) Store in a stabilized manner, away from slopes, vibration and shock (during transportation as well). �) Store away from direct sunlight. �) Store away from a place where you keep chemicals or a place vulnerable to gas generation. [Storage of the Thermometer] [Conformity Authentication] [Medical Device Certification Information] [Compatible Devices] [SUPPORT] Please contact us about any problems you have encountered with the Product or suggestions for improvement. ※ Why Thermosafer? Class B Device (Broadcasting Communication Device for Home Use) This device obtained EMC registration mainly for home use (Class B) and may be used in all areas. · Guardians often stay awake at night to monitor a patient’s body temperature during a fever. Thermosafer provides valuable features, such as real-time body temperature monitoring and customizable alarms for abnormal temperature readings, allowing caregivers to rest while ensuring the patient's condition is monitored safely. · The recorded data is stored on the app on your smartphone and can be shared with your physician during hospital visits, aiding in accurate diagnosis. ※This product is a "Medical Device", disposable(Non-reusable) Designed by CHOISTECHNOLOGY THERMOSAFER Electronic Thermometer �� -�� CT-IM_2025.10.16 _ rev.1.1 received, including interference that may cause undesired operation.

FCC ID: RVBXST600 According to KDB 447498 D04 Interim General RF Exposure Guidance v01 1. SAR-based Exemption A more comprehensive exemption, considering a variable power threshold that depends on both the separation distance and power, is provided in § 1.1307(b)(3)(i)(B). This exemption is applicable to the frequency range between 300 ㎒ and 6 ㎓, with test separation distances between 0.5 ㎝ and 40 ㎝, and for all RF sources in fixed, mobile, and portable device exposure conditions. Accordingly, a RF source is considered an RF exempt device if its available maximum time-averaged (matched conducted) power or its effective radiated power (ERP), whichever is greater, are below a specified threshold. This exemption threshold was derived based on general population 1-g SAR requirements and is detailed in Appendix C. 2. RF Exposure Test Exemptions for Single Source Mode Frequency Range (㎒) Minimum Separation Distance (㎝) Maximum Average Target Power (㏈m) Maximum Tune up (㏈) Maximum Average Output Power Antenn a Gain (㏈i) ERP P th (㎽) Ratio 1) Result (㏈m) (㎽) (㏈m) (㎽) Bluetooth Low Energy 2 402 ~ 2 480 0.5 3.2 1.0 4.2 2.63 -13.60 -10.75 0.08 2.717 0.97 Pass Note ; - Maximum average target power is the manufacturer’s declared rated power. - ERP(㏈m) = Maximum average output power(㏈m) + Antenna gain(㏈i) - 2.15 - Threshold level calculation; Bluetooth Low Energy (2 402 ㎒ ~ 2 480 ㎒) - Maximum average output power(㏈m) = Maximum average target power(㏈m) + Maximum tune up(㏈). 1) A greater value between the ERP(㏈m) and the Maximum Average Output Power(㏈m) is applied. 3. Conclusion: No SAR is required.

Item Contents Antenna Type Chip Antenna Antenna peak gain -13.60 ㏈i Manufacturer / Model name Chois Technology Co., Ltd. / - Address of manufacturer S-1404, 32, Songdogwahak-ro, Yeonsu-gu, Incheon, South Korea Test Laboratory Electromagnetic Wave Technology Institute Antenna Length 1.5 mm Antenna Width 4 mm Antenna Information Width Length 2D Radiation Pattern

SGS Korea Co., Ltd. 4, LS-ro 182beon-gil, Gunpo-si, Gyeonggi-do, Korea, 15807 Tel. +82 31 428 5700 / Fax. +82 31 427 2370 http://www.sgsgroup.kr Report Number: F690501-RF-RTL006882-1 Page: 2 of 35 RTT7081-02(2020.10.05)(0) A4(210 mm * 297 mm) INDEX Table of contents 1. General Information -------------------------------------------------------------------------------------- 3 2. Transmitter Radiated Spurious Emissions and Conducted Spurious Emissions ---------- 8 3. 6 ㏈ Bandwidth and 99 % Bandwidth----------------------------------------------------------------- 23 4. Maximum Peak Conducted Output Power --------------------------------------------------------- 28 5. Power Spectral Density --------------------------------------------------------------------------------- 32 6. Antenna Requirement ----------------------------------------------------------------------------------- 35 SGS Korea Co., Ltd. 4, LS-ro 182beon-gil, Gunpo-si, Gyeonggi-do, Korea, 15807 Tel. +82 31 428 5700 / Fax. +82 31 427 2370 http://www.sgsgroup.kr Report Number: F690501-RF-RTL006882-1 Page: 3 of 35 RTT7081-02(2020.10.05)(0) A4(210 mm * 297 mm) 1. General Information 1.1. Testing Laboratory SGS Korea Co., Ltd. (Gunpo Laboratory) - 10-2, LS-ro 182beon-gil, Gunpo-si, Gyeonggi-do, Korea, 15807 - 4, LS-ro 182beon-gil, Gunpo-si, Gyeonggi-do, Korea, 15807 - Designation number: KR0150 All SGS services are rendered in accordance with the applicable SGS conditions of service available on request and accessible at http://www.sgs.com/en/Terms-and-Conditions.aspx. Phone No. : +82 31 688 0901 Fax No. : +82 31 688 0921 1.2. Details of Applicant Applicant : Chois Technology Co., Ltd. Address : S-1404, 32, Songdogwahak-ro, Yeonsu-gu, Incheon, South Korea Contact Person : Son, Dae-heung Phone No. : +82 70 5121 2134 1.3. Details of Manufacturer Company : Same as applicant Address : Same as applicant 1.4. Description of EUT Kind of Product Thermoasafer Model Name XST600 Serial Number XST-600-001 Power Supply DC 3.0 V Frequency Range 2 402 ㎒ ~ 2 480 ㎒ (Bluetooth Low Energy) Modulation Technique GFSK Number of Channels 40 channels (Bluetooth Low Energy) Antenna Type Chip Antenna Antenna Gain ※ -13.60 ㏈i H/W Version V1.0 S/W Version V1.0 SGS Korea Co., Ltd. 4, LS-ro 182beon-gil, Gunpo-si, Gyeonggi-do, Korea, 15807 Tel. +82 31 428 5700 / Fax. +82 31 427 2370 http://www.sgsgroup.kr Report Number: F690501-RF-RTL006882-1 Page: 4 of 35 RTT7081-02(2020.10.05)(0) A4(210 mm * 297 mm) 1.5. Test Equipment List Equipment Manufacturer Model S/N Cal. Date Cal. Interval Cal. Due Spectrum Analyzer 1) R&S FSV30 103102 03/21/2025 Annual 03/21/2026 03/17/2026 03/17/2027 Spectrum Analyzer Agilent N9020A MY53421758 09/10/2025 Annual 09/10/2026 Spectrum Analyzer Agilent N9030A US51350132 12/03/2025 Annual 12/03/2026 Attenuator AEROFLEX/INMET 40AH2W-6 1 03/09/2026 Annual 03/09/2027 High Pass Filter Wainwright Instrument GmbH WHKX3.0/18G-10SS 21 06/17/2025 Annual 06/17/2026 High Pass Filter Wainwright Instrument GmbH WHNX7.5/26.5G-6SS 15 06/09/2025 Annual 06/09/2026 Low Pass Filter Mini-Circuits NLP-1200+ V8979400903-2 02/02/2026 Annual 02/02/2027 DC Power Supply AGILENT U8002A MY54110041 09/18/2025 Annual 09/18/2026 Preamplifier H.P. 8447F 2944A03909 08/07/2025 Annual 08/07/2026 Signal Conditioning Unit R&S SCU-18F 100959 01/05/2026 Annual 01/05/2027 Preamplifier TESTEK TK-PA1840H 130016 03/06/2026 Annual 03/06/2027 Loop Antenna Schwarzbeck Mess- Elektronik FMZB 1519 1519-039 10/01/2025 Biennial 10/01/2027 Bilog Antenna Schwarzbeck Mess- Elektronik VULB 9163 01126 03/09/2026 Biennial 03/09/2028 Horn Antenna R&S HF906 100326 03/03/2026 Annual 03/03/2027 Horn Antenna Schwarzbeck Mess- Elektronik BBHA 9170 9170-540 12/05/2025 Annual 12/05/2026 EMI Test Receiver R&S ESU26 100109 01/21/2026 Annual 01/21/2027 Turn Table Innco systems GmbH DS 1200 S N/A N.C.R. N/A N.C.R. Controller Innco systems GmbH CONTROLLER CO3000-4P CO3000/963/3833 0516/L N.C.R. N/A N.C.R. Antenna Mast Innco systems GmbH MA4640-XP-ET MA4640/536/3833 0516/L N.C.R. N/A N.C.R. Anechoic Chamber SY Corporation L × W × H (9.6 m × 6.4 m × 6.6 m) N/A N.C.R. N/A N.C.R. Coaxial Cable SENSORVIEW NMST-13A26-NMST- 5 m TPC2402190004 10/13/2025 Semi- Annual 04/13/2026 Coaxial Cable SENSORVIEW NMST-13A26-NMST- 10 m TPC2402190001 10/13/2025 Semi- Annual 04/13/2026 Coaxial Cable RFONE PL360P-292M292M- 1.5M-A 20200324002 10/10/2025 Semi- Annual 04/10/2026 Note; 1) The equipment was not used for testing during the period from 03/13/2026 to 03/19/2026. SGS Korea Co., Ltd. 4, LS-ro 182beon-gil, Gunpo-si, Gyeonggi-do, Korea, 15807 Tel. +82 31 428 5700 / Fax. +82 31 427 2370 http://www.sgsgroup.kr Report Number: F690501-RF-RTL006882-1 Page: 5 of 35 RTT7081-02(2020.10.05)(0) A4(210 mm * 297 mm) 1.6. Declaration by the Manufacturer - The EUT supports BLE version 5.1 and only operates PHY 1M 1.7. Summary of Test Results The EUT has been tested according to the following specifications: APPLIED STANDARD: FCC Part 15 Subpart C Section in FCC Test Item(s) Result 15.205(a) 15.209 15.247(d) Transmitter Radiated Spurious Emissions and Conducted Spurious Emission Pass 15.247(a)(2) 6 ㏈ Bandwidth & 99 % Bandwidth Pass 15.247(b)(3) Maximum Peak Conducted Output Power Pass 15.247(e) Power Spectral Density Pass 15.207 AC Power Line Conducted Emission N/A 1) Note; 1) The AC power line test was not performed because the EUT use battery power for operation and which do not operate from the AC power lines. 1.8. Test Procedure(s) The measurement procedures described in the American National Standard of Procedure for Compliance Testing of unlicensed Wireless Devices (ANSI C63.10-2020) and the guidance provided in KDB 558074 D01 15.247 Meas Guidance v05r02 were used in the measurement of the DUT. 1.9. Sample Calculation Where relevant, the following sample calculation is provided: 1.9.1. Radiation Test Field strength level (㏈㎶/m) = Measured level (㏈㎶) + Antenna factor (㏈/m) + Cable loss (㏈) - Amplifier gain (㏈) + Duty factor (㏈) 1.10. In…

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