1、Built‑in 250MAH rechargeable battery, long endurance, it can work for a long time. 2、Both RX and TX modes are supported, stereo design, provides you with better sound quality. 3、The state mode can be switched freely during work, which can meet your different needs. 4、The connection is simple, without any tedious operation of driving and downloading APP. 5、Compatible for Android, for IOS system mobile phones and PAD, supports Bluetooth speakers or earphones with A2DP protocol. 1 x Bluetooth Adapter 1 x 3.5mm Audio Cable 1 x Micro USB Power Supply Cable1 x Operation Manual  Condition: 100% Brand NewItem Type: Audio Receiver TransmitterMaterial: ABSColor: BlackBluetooth Version: Bluetooth V 5.0Support Protocol: RX: A2DP, AVRCP TX: A2DPWorking Frequency Band: 2.402GHz - 2.480GHzPower Level: Class II (Class II)Audio Coding: RX: SBC, AAC TX: SBCFunctions: Support RX And TX Modes Working Current: RX＜26MA TX＜24MABuilt-In Battery: 250MAHCharging Time: About 2 HoursLife Time: >8HBluetooth Distance: >10M (Open Place)Charging Method: Micro USB 5V/ 0.5AInput/Output Connection Mode: AUX (headphone) interfaceCompatible: for Android, for IOS system mobile phone and PAD, and Bluetooth speakers or earphones supporting A2DP protocol to connect and use