It can connect two devices, support to connect with 3.5mm audio port and 2 RCA audio port at the same time A built-in microphone for hands-free calls Simple button operations to answer/hang-up calls, switch songs and adjust volume Ultra-compact and lightweight for convenient use with a variety of devices Upgraded to support U Disk play No built-in battery, powered by USB Specification: Support devices: support two mobile phones to connect Bluetooth version: 5.0 Output interface: 3.5mm stereo RCA left and right channels Function: support U disk, hands-free call, NFC connection Bluetooth protocol: AVRCP, A2DP Frequency range: 2400-2483.5MHz Frequency response: 20Hz-20kHz Output power: 28mW RL=16Ω Signal to noise ratio: andgt 90dB Total harmonic distortion: andlt 0.1 percent Forward transmission distance: 10 meters Power supply: Micro USB interface 5V power supply Size: 78x48x18mm Note: Due to the light and screen setting difference, the item's color may be slightly different from the pictures. Please allow slight dimension difference due to different manual measurement. Sold by-Minnanxin