CSR 2 In 1 Wireless Bluetooth 5.0 Transmitter Receiver Audio Adapter Long Battery Life Item Type: Bluetooth Transmitter Receiver Material: ABS Color: As Pictures Shown Weight: Approx. 166g/5.9ozBluetooth Version: Bluetooth V5.0 Support Protocol: RX: A2DP AVRCP TX: A2DP Operating Frequency: 2.402GHz -2.480GHz Power Level: Power Level 1, 2 (Class I II) Distortion: ≤0.1% Support Dual Stream (TX Mode) : Support (one Transmitter is Connected to Two Bluetooth Speakers or Earphones Simultaneously Using a CODEC, Up to APTX LL) Support Multipoint(RX mode) : Support (connect two phones) CODEC: TX: for apt-X LL/apt-X/ SBC/FS  RX: for apt-X LL/apt-X/SBC/AAC/FS APTX Usage Note: apt-X LL CODEC is Preferred for Single Connection (all Devices Must Also Support apt-X LL) Built-in Battery: 500mAh Charging Current: About 350mA Charging Time: About 2.5 Hours Endurance: RX is More Than 10h, TX Average About 8h Bluetooth Distance: > 80m/262.5ft(no shelter) Charging Mode: Micro USB 5V/ 0.5A Input/output Connection Mode: for RCA Interface, I2S AUX Interface, Support for RCA and Aux Double-channel Simultaneous Output Compatible for Android/IOS System Mobile Phone and Pad, and Support A2DP Bluetooth Speaker or Headset Connection Use