IN: 3.7V-5V DCSignal to noise :90DB; harmonic distortion: -70dB; Crosstalk: -86DBSupport configuration file :HFP/A2DP/AVRCP/AVCTPV/AVDTPV/Transmission distance :15MDecoding :WAV+APE+FLAC+MP3: bt5.0 audioBluetooth audio: supportAudio external interfacel: SupportUSB powered: supportSound card function: support gold craft: SupportBattery powered: SupportCharge while putting: NO supportKey control: NO supportVoice calls: NO supportMute control(MUTE): NO supportBluetooth version: Bluetooch V5.0Decoding : HFPV1.7, A2DPV1.2, AVRCPV1.5, AVCTPV1.2AVDTPV1.2color:BlackMaterial:ABSPackage Contents:20 x Audio Receiver(without battery)Only the above package content, other products are not included.Note: Light and different displays may the color of the item in the a little different from the real thing. The measurement allowed error is +/- 1-3cm.