1、Using Bluetooth V0, the connection is stable. Bluetooth supports A2DP, AVRCP, HFP, HSP. 2、The transmitting state supports two Bluetooth devices to connect and play simultaneously. 3、Support Bluetooth receiving/Bluetooth transmitting. Support AUX audio input/audio output 4、Built-in 280mAh lithium battery, full-charged music playback time is about 7 hours. 5、Automatically connect back to the paired Bluetooth device after power-on, and automatically shut down if there is no device connection for five minutes. 1 x Audio Adapter 1 x Audio Cable1 x Charging Cable   1 x Manual Item Type: Bluetooth Audio AdapterMaterial: ABSColor: As Pictures Shown Size: Approx. 65x39x16mm/ 2.6x 1.5x 0.6inWeight: Approx. 71g/ 2.5ozCharging Voltage: 5VCharging Current :150mAOperating Current :35mAShutdown Current :41uACharging Time: about 2HWorking Hours: about 7 hoursBattery Capacity :280mAhBluetooth Version :Version 5.0Bluetooth Sound Processing: for DSP Technology and A2DP(Advance Audio Distribution Profile) FunctionBluetooth Frequency : 2.402- 2.480GHzBluetooth Transmission Distance: Straight Line 10M/ 32.8ftBluetooth Microphone Effective Distance : 0.5-2M/ 19.7- 78.7ftBluetooth Transmission Output Power: 6dBm