2BXCT-89041CUS0626WIRELESS BEHIND THE NECK EARBUDS

1/1 USAgentforServiceofProcessLETTEROFATTESTATION TO: OfficeofEngineeringTechnology FederalCommunicationsCommission 7435OaklandMillsRoad Columbia,MD21046 USAgentforServiceofProcess: CompanyName:LindenHoldingsII.LLC,anIowalimitedliabilitycompany FRN:0038697306 ContactName:RonLuo Address:9300EarhartLane,SW,CedarRapids,IA,52404 TelephoneNo:319-294-3734 Email:[email protected] Applicant: Companyname:LindenHoldingsII.LLC,anIowalimitedliabilitycompany ProductDescription:WIRELESSBEHINDTHENECKEARBUDS FRN:0038697306 FCCID:2AF9P-SUDIOPLAYMINI ContactName:RonLuo Address:9300EarhartLane,SW,CedarRapids,IA,52404 TelephoneNo:319-294-3734 Email:[email protected] [LindenHoldingsII.LLC,anIowalimitedliabilitycompany]certifiesthat,asof thedateofthisfilingoftheapplicationwiththeTCB,[LindenHoldingsII.LLC, anIowalimitedliabilitycompany]isourdesignatedUSagentforserviceof processfortheabovereferencedFCCID.[LindenHoldingsII.LLC,anIowa limitedliabilitycompany]acceptstomaintainanagentfornolessthanone yearafterthegranteehasterminatedallmarketingandimportationorthe conclusionofanycommissionrelatedproceedinginvolvingequipment.[Linden HoldingsII.LLC,anIowalimitedliabilitycompany]accepts,asofthedateof thefilingoftheapplication,theobligationofthedesignatedUSagentfor serviceofprocessfortheabovereferenceFCCID. TheUSAgentforServiceofProcessisawareofandagreestocomplywiththerequirements outlinedintheFCCEquipmentAuthorizationProgram,ReportandOrderFCC22-84,andclause §2.911. TheApplicantisawareofandagreestocomplywiththerequirementsoutlinedintheFCC EquipmentAuthorizationProgram,ReportandOrderFCC22-84,andclause§2.911. Date:2026/08/28 Applicant’sName:RonLuoUSAgent’sName:RonLuo Title:SalesTitle:Sales SignatureSignature

AttestationStatement. OldCode:C526609124NewCode:00015544Ed.3 Changereason:FRNisaddedtotheApplicantinformationsection. 1/1 TO: OfficeofEngineeringTechnology FederalCommunicationsCommission 7435OaklandMillsRoad Columbia,MD21046 TheCommissionadoptedrulesthatprohibitequipmentauthorizationfor“covered” telecommunicationsequipmentandvideosurveillanceequipmentproducedbyentitiesidentified ontheCommission’sCoveredList 1 ,whichisperiodicallyupdated.SeetheCoveredListformore details.ThisAttestationStatementistoconfirmthatwefollowtheSection2.911(d)(5)(i)-(ii) Applicant Companyname:LindenHoldingsII.LLC,anIowalimitedliabilitycompany Granteecode:2BXCT FCCID:2BXCT-89041CUS0626 FRN:0024985681 ContactName:RonLuo Address:9300EarhartLane,SW,CedarRapids,IA,52404 TelephoneNo:319-294-3734 FaxNo:319-393-3494 Email:[email protected] i.[LindenHoldingsII.LLC,anIowalimitedliabilitycompany](“theapplicant”) certifiesthattheequipmentforwhichauthorizationissoughtisnot“covered” equipmentprohibitedfromreceivinganequipmentauthorizationpursuantto section2.903oftheFCCrules.Theapplicantmustsignthiscertification. ii.[LindenHoldingsII.LLC,anIowalimitedliabilitycompany](“theapplicant”) certifiesthat,asofthedateofthefilingoftheapplication,theapplicant[is not](asaspecificallynamedentityoranyofitssubsidiariesoraffiliates) identifiedontheCoveredListasanentityproducing“covered”equipment. Theapplicantmustsignthiscertification. [LindenHoldingsII.LLC,anIowalimitedliabilitycompany](“theapplicant”) certifiesthat,asofthedateofthefilingofthe application,theapplicant[isnot]identifiedontheCoveredList asanentityproducing“covered” equipment. Date:2026-08-28 Applicant’sName:RonLuo Title:Sales Signature 1 TheCommission’sCoveredListispublishedbythePublicSafetyandHomelandSecurityBureauandpostedonthe Commission’swebsite.ThisCoveredList,whichisperiodicallyupdated,identifiesparticularequipment,producedbyparticular entities,thatconstitutes“covered”equipment.https://www.fcc.gov/supplychain/coveredlist

LindenHoldingsII.LLC,anIowalimitedliabilitycompany Code00018768Ed.1 Item1.Thedeviceisabletoinstallsoftware/programinstallation? ☐ Yes,gotoItem2. ☒ No.Inthiscase,therestoftheitemsdonotapply.ThedevicecannotsupportinstallationofKaspersky cybersecurityoranti-virussoftware. DeviceWIRELESSBEHINDTHENECKEARBUDS CompanynameLindenHoldingsII.LLC,anIowalimitedliability company Granteecode2BXCT FCCID2BXCT-89041CUS0626 FRN0038697306 ContactnameRonLuo Address9300EarhartLane,SW,CedarRapids,IA,52404 Telephonenumber319-294-3734 [email protected] Chipset/moduleinformationAC7023E2 OperatingSystem(ifapplicable)N/A StorageCapacity(harddriveorother permanentmemorystorage,ifapplicable) N/A 2 Item2.TechnicalRequirementsforKasperskyCybersecuritySoftware: #GeneralRequirements(ForallDevices)Yes/NoorN/AComments 1Internetconnectionforactivationandupdates(ForallOperating Systems) N/A #GeneralRequirements(ForWindowsDevices)Yes/NoorN/AComments 1Storage:1500MBfreespaceontheharddriveN/A 2OperatingSystem: MicrosoftWindows8,8.1,10&11Home/Pro/Enterprise Microsoft Windows7Starter/HomeBasic&Premium/Professional/ UltimateSP1orhigher N/A 3Processor:1GHzorhigher(x86orx64)N/A 4Memory(RAM)1GB(32-bit)or2GB(64-bit)N/A 5ScreenResolution:Minimumresolutionof1024x768N/A #GeneralRequirements(FormacOSdevices)Yes/NoorN/AComments 1OperatingSystemmacOS®13–14N/A 2Memory(RAM)4GBN/A 3Storage:3455MBfreespaceontheharddriveN/A #GeneralRequirements(ForAndroidDevices)Yes/NoorN/AComments 1Storage:150MBfreespaceN/A 2OperatingSystem:Android™10–14N/A 3ScreenResolution:Minimumresolutionof320x480N/A #GeneralRequirements(foriOSdevices)Yes/NoorN/AComments 1Storage:150MBfreespaceN/A 3 2OperatingSystem:iOS®17N/A #GeneralRequirements(ForLinuxsystem)Yes/NoorN/AComments 1Harddrive:1GBoffreespaceN/A 2CPU:IntelPentium1GHzorhigherN/A 3RAM:1GBN/A 4Minimumsoftwarerequirements: AlmaLinuxOS8orlater; AlterOS7.5orlater; AstraLinuxCommonEdition2.12orlater; CentOS6.7orlater; DebianGNU/Linux10.0orlater; EulerOS2.0orlater; OracleLinux7.3orlater; RedHatEnterpriseLinux6.7orlater; RockyLinux8.5orlater; SUSELinuxEnterpriseServer12.5orlater; Ubuntu12.04orlater; UncomOSHome/Business/Education/Enterprise2.2orlater; ALTLinuxWorkstaton/WorkstationK/Server/Education8or later; ROSALinuxWorkstation/Server12orlater; REDOS7.3andlater; N/A Afterreviewedthetechnicalrequirements,isthedevicecapableofsupportingtheinstallationof Kasperskysoftware? ☐Yes,gotoItem3. 4 ☒No.Inthiscase,therestoftheitemsdonotapply.ThedevicecannotsupportinstallationofKaspersky software Item3.ConnectivityCapabilities: #PhysicalInterfacePurposeJustification 1 1 #WirelessInterfacePurposeJustification 1 1 Afterthereviewofthisitems,thedevice: ☒Cannotsupportinstallationofanycybersecurityoranti-virussoftwareonthecoveredlist. ☐Potentiallycanoperatewithanycybersecurityoranti-virussoftwareonthecoveredlist–additionalthird- partyproofisprovidedtodemonstratecompliancewithrequirementsasof2.911(d)5(i),(ii)–“Proofof CompliancewithCoveredListSoftwareRequirements”ofthisdocumentapplies Signature:Name:RonLuo Date:2026-08-28 1 Thejustificationfieldisusedtojustifywhythesoftwarecannotbereceivedthroughthatinterface.Checktheannexformore indications.

TCB CALL página 1 File FCC ID: 2BXCT-89041CUS0626 Please upload an exhibit that explains how does the TCB verify the new agent information: 1- Is the address of the agent a valid physical US mailing address (not a US post office box, not a virtual mailbox, not P.O. Boxes, not a vacant lot, not a public building, etc.) ○ We have checked if the address exists in a real and potential building (Google maps) + official US register, after this verification and the evidence below we can guarantee the following: not a US post office box not a virtual mailbox not P.O. Boxes not a vacant lot not a public building(note) ► We checked the FCC FRN Search based on the information provided by the grantee. On the official register from : https://sos.iowa.gov/search/business/summary.aspx?q=O9imWfzIk-48Fl5IQmzjCNmGoEokzmhntfzjikKrMwta6-6G2cclPU7iqc315BTF1Shw- ULWg0VpFWLLBFcYe6xmBWU4dGkG0YOy8U3Rw3C7Q0iFZrXywLOMVM5_dKIIvvlx_xYrAM138qmSl4yhj_gZA0yuX6WfB-5USmxLjyPa0PK1i2DOAz- 526EWtGs8dDiQvPkwcvB_s37yObTghRdyrv6AWlgUF68ySHvajaBHgshlpvCuIVJbuBNEp8rvSXyLf_VXywZZtyRPHIwRla-WITPInee458Sh1upTCZjPuIx-P_b6CJvPqyInN_XiXPklcyYNzTR8Cm_mx6y90V1KFAR37aKOyTN8vaA9t_- Oiebn5N2f0qfFKoBMTKCkIwfKhgQCWXC1Gwn7hXWJm0b8C0zF5quAHNq09kwhGTw1 TCB CALL página 2 In google: TCB CALL página 3 ► CONCLUSION by TCB: The ASOP defined and provided by grantee is VALID and confirmed. Therefore the exhibit "C5266091_X23_Ed1_US_Agent_Letter" included in the file is ok. 2- Is the agent physically located at that valid US address such that the agent can be legally served at that address? Yes , check above 3- Has the listed agent clearly agreed in writing to serve as the agent for the grantee at that address? Yes, it is included in the exhibit "C5266091_X23_Ed1_US_Agent_Letter" >

C5266091_X10_Ed.2 1/1 LindenHoldingsII.LLC,anIowalimitedliabilitycompany OfficeofEngineeringTechnology FederalCommunicationsCommission 7435OaklandMillsRoad Columbia,MD21046 Date:2026-08-28 Subject:RequestforConfidentiality FCCID:2BXCT-89041CUS0626 ToWhomItMayConcern, PursuanttotheprovisionsofSections0.457and0.459ofCommission'srules (47CFR0.457,0.459),wearerequestingtheCommissiontowithholdthefollowing attachment(s)asconfidentialdocumentfrompublicdisclosure. ExhibitsLong-Term Confidentiality Short-Term Confidentiality NOTE2 IDLabel/LocationNoNo AttestationStatementNoNo ExternalPhotosNo ☒ BlockDiagram ☒☐ Schematics ☒☐ TestReportNoNo TestSetupPhotosNo ☒ User’sManual ☐ NOTE 1 ☒ InternalPhotos ☐ NOTE 1 ☒ PartsList/TuneUp ☐☐ RFExposureInfoNoNo OperationalDescription ☒☐ CoverLetter(s)NoNo SDRSoftware/SecurityInfo ☐ No NOTE1:Long-TermConfidentialitymaybepermittedunderspecialconditions(SeeII.LONG-TERMCONFIDENTIALITY,Section3of KDB726920,uselastinforce) NOTE2:Short-TermConfidentialitycanberequestedforamaximumof180daysfromthedateofthegrant. Abovementioneddocumentcontainsdetailedsystemandequipmentdescriptionare consideredasproprietaryinformationinoperationoftheequipment.Thepublic disclosureofabovedocumentsmightbeharmfultoourcompanyandwouldgive competitoranunfairadvantageinthemarket. Incaseofshort-termConfidentiality,theapplicantrequeststheexhibitsselected abovearewithheldfrompublicviewforaperiodof_180__daysfromthedateofthe GrantofEquipmentAuthorizationandpriortomarketing. Itisourunderstandingthatallmeasurementtestreports,FCCIDlabelformatand correspondentduringcertificationreviewprocesscannotbegrantedasconfidential documentsandthoseinformationwillbeavailableforpublicreviewoncethegrantof equipmentauthorizationisissued. C5266091_X10_Ed.2 1/1 Sincerely, Signature: Name:RonLuo Title:Sales

C5266091_X8_Ed.1 1/1 LetterofAuthorization <LindenHoldingsII.LLC,anIowalimitedliability company> Company:LindenHoldingsII.LLC,anIowalimitedliability company Address:9300EarhartLane,SW,CedarRapids,IA,52404 ProductName:WIRELESSBEHINDTHENECKEARBUDS ModelNumber:89041 FCCIdentifier:2BXCT-89041CUS0626 WeauthorizeLGAITechnologicalCenterS.A.,RondadelaFontdelCarme,s/n, 08193Bellaterra,Spain,toactonourbehalfonallmattersconcerningthe abovenamedequipment. AnyindividualwithinLGAITechnologicalCenterS.A.isauthorizedtoactonour behalfandtakeactionontheapplication. WedeclarethatauthorizeLGAITechnologicalCenterS.A.,RondadelaFontdel Carme,s/n,08193Bellaterra,Spain,isallowedtoforwardallinformation relatedtotheapprovalprojecttotheFederalCommunicationCommissionand todiscussanyissuesconcerningtheapprovalapplication.Anyandallacts carriedoutbyLGAITechnologicalCenterS.A.onourbehalfshallhavethe sameeffectasactsofourown. Name:RonLuoDate:2026-08-28 Title:Sales Signatureofapplicant:

Label & Label Location On EUT Size: 10*15mm Confirm the use of real appearance photos as references. FCC ID: 2BXCT-89041CUS0626

RFEXPOSUREEVALUATION FCCID:2BXCT-89041CUS0626 AccordingtoKDB447498D01GeneralRFExposureGuidancev06andFCC 1.1310:Thecriterialistedinthefollowingtableshallbeusedtoevaluatethe environmentimpactofhumanexposuretoradiofrequency(RF)Radiationas specifiedin§1.1307(b): RoutineSARevaluationreferstothatspecificallyrequiredby§2.1093,using measurementsorcomputersimulation.WhenroutineSARevaluationisnot required,portabletransmitterswithoutputpowergreaterthantheapplicable lowthresholdrequireSARevaluationtoqualifyforTCBapproval. Channel (MHz) Maximum outputpower (dBm) Tuneup tolerance (dBm) MaxTune UpPower (dBm) Distance (mm) Calculation results Limit Operating Mode 24022.592.59±13.5950.7083 BT 24413.463.46±14.4650.8733 24803.883.88±14.8850.9693 24023.543.54±14.5450.8823 24414.354.35±15.3551.0713 24804.754.75±15.7551.1843 24023.803.80±14.8050.9363 24414.674.67±15.6751.1533 24805.085.08±16.0851.2773 TestResults:PASS.

TESTREPORT ReportNo.:8433EU122002W Applicant:LindenHoldingsII. LLC,an Iowalimitedliability company Address:9300EarhartLane,SW, CedarRapids,IA, 52404 ProductName:WIRELESSBEHINDTHE NECKEARBUDS ModelNo.:89041 Trademark: FCC ID:2BXCT-89041CUS0626 Test Standard(s):47 CFRPart 15.247 Test Result:Pass Dateof Receipt:Jul. 20, 2026 Test Date:Jul. 21, 2026- Aug.05, 2026 Dateof Issue:Aug.28, 2026 ISSUEDBY: SHENZHENEU TESTINGLABORATORYLIMITED Preparedby:Reviewedand Approvedby: PeachZheng/EngineerSallyZhang/Manager Page2 of 116ReportNo.: 8433EU122002W TRF Version:A01 RevisionRecord ReportVersionIssuedDateDescriptionStatus V0Aug.28, 2026OriginalValid Page3 of 116ReportNo.: 8433EU122002W TRF Version:A01 Tableof Contents 1COVERPAGE...................................................................................................................................................1 2GENERALINFORMATION........................................................................................................................5 2.1APPLICANTINFORMATION...................................................................................................................5 2.2MANUFACTURERINFORMATION...........................................................................................................5 2.3FACTORYINFORMATION......................................................................................................................5 2.4GENERALDESCRIPTIONOFE.U.T......................................................................................................5 2.5TECHNICALINFORMATIONOFE.U.T....................................................................................................6 3TESTSUMMARY.......................................................................................................................................7 3.1TESTSTANDARD................................................................................................................................7 3.2TESTVERDICT...................................................................................................................................7 3.3TESTLABORATORY............................................................................................................................9 4TESTCONFIGURATION.........................................................................................................................10 4.1TESTENVIRONMENT.........................................................................................................................10 4.2TESTEQUIPMENT.............................................................................................................................10 4.3DESCRIPTIONOFSUPPORTUNIT......................................................................................................13 4.4TESTMODE.....................................................................................................................................13 4.5DESCRIPTIONOFCALCULATION........................................................................................................13 4.5.1FieldStrengthCalculation..................................................................................................13 4.5.2DisturbanceCalculation.....................................................................................................13 4.6MEASUREMENTUNCERTAINTY..........................................................................................................14 4.7DEVIATIONFROMSTANDARDS..........................................................................................................14 4.8ABNORMALITIESFROMSTANDARDCONDITION..................................................................................14 5EVALUATIONRESULTS(EVALUATION)..............................................................................................15 5.1ANTENNAREQUIREMENT..................................................................................................................15 5.1.1Test Specification...............................................................................................................15 5.1.2Test Data ............................................................................................................................15 6RADIOSPECTRUMMATTERTESTRESULTS(RF) ............................................................................16 6.1CONDUCTEDEMISSIONATACPOWERLINE......................................................................................16 6.1.1Test Specification...............................................................................................................16 6.1.2E.U.T.Operation.................................................................................................................16 6.1.3Test SetupDiagram...........................................................................................................16 6.1.4Test Data ............................................................................................................................16 6.220DB BANDWIDTH...........................................................................................................................19 6.2.1Test Specification...............................................................................................................19 6.2.2E.U.T.Operation.................................................................................................................20 6.2.3Test SetupDiagram...........................................................................................................20 6.2.4Test Data ............................................................................................................................20 6.3MAXIMUMCONDUCTEDOUTPUTPOWER...........................................................................................21 6.3.1Test Specification.................................................................…

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Inverted F Antenna Specification Summary ITEMANT SPEC Model Name 2.4G ANT HorizontalVertical 2400MHz 2400MHz2500MHz2400MHz2400MHz 2500MHz Center Frequency -1.26-0.76-0.58-5.25-2.46-1.86 MAX. Gain -0.58dBi PolarizationHorizontal and Vertical Azimuth Beam Pattern Omni-directional Impedance50 Ohm Manufacture Address ZHUHAI JIELI TECHNOLOGY CO.,LTD Antenna Photo & Length (mm) Building 9, Jinshi Garden, No. 107 Shihua West Road, Xiangzhou District, Zhuhai City, Guangdong Pr ovince, China Horizontal: 2400 MHz 2450 MHz 2500 M Hz Power (dBi) Max : 0 Min: -40 Scale: 5/div Gain(dBi) Frequency (MHz) MaxMinAvg 2400-1.26174-30.0801-7.18716 2450-0.765802-36.5604-7.48023 2500-0.585582-22.0315-6.59127 Vertical: 2400 MHz 2450 MHz 2500 M Hz Power (dBi) Max : 0 Min: -30 Scale: 5/div Gain(dBi) Frequency (MHz) MaxMinAvg 2400-5.2537-22.1424-12.4294 2450-2.4652-24.5837-10.4702 2500-1.86120-29.5214-9.20432 ANT Test Labs：Attestation of Global Compliance Co., Ltd.