Specifications : Support Equipment: Support the connection of two mobile phones Bluetooth Version: 5.0 Output interface: 3.5mm AUX stereo/RCA left and right channels Function description: U disk, hands-free call, NFC connection,Bluetooth connection. Bluetooth protocol: AVRCP, A2DP Frequency range: 2400-2483.5MHz Frequency response: 20Hz-20kHz Output power: 28mW RL=16Ω Signal-to-noise ratio: 90dB Total harmonic distortion: 0.1% Support: SBC, AAC Forward transmission distance: 10m Product size 78*50*18 (mm) Support Multiple Audio Output Ports: Can Connect With 3.5mm Headset, Stereo System, Speaker System Support: All Bluetooth audio device; NFC Available Device. Note: No built in battery,So POWERED BY USB CHARGING. Package Content: 1x Bluetooth 5.1 Audio Receiver Adapter 1x 3.5mm Aux Cable 1x User Manual