Features: 1. Bluetooth V5.3 2. Supports Bluetooth reception/Bluetooth transmission 3. Automatically reconnect to paired Bluetooth devices upon startup 4. No device connection for 3 minutes, automatic shutdown 5. The music playback time is about 7.5 hours when fully charged 6 Bluetooth supports A2DP, AVCTP, AVDTP, AVRCP, HFP, SPP 7. Supports Bluetooth stereo music DSP technology 8. AUX audio input/audio output 9: Support TF card playback 10. Can be used directly as an MP3 player, with headphones plugged in and Product Introduction: This product is an intelligent Bluetooth transceiver that supports two modes: Bluetooth reception and Bluetooth transmission; Typical use cases include transmitting mobile music to home speakers, car speakers, or CD players, MP3 players, computers, and other audio devices to headphones, speakers, and other scenarios; Flexible use with low distortion, low power consumption, low latency, high fidelity, and simple and convenient stereo operation. Charging limit voltage: 5.25V Charging current: 300mA [Working current] On screen: RX mode: 62mATX mode: 72mA In off screen mode: RX mode: 20mA TX mode: 30mA Shutdown current: 20uA Charging time: approximately 35 minutes Working hours: RX mode: approximately 7.5H TX mode: approximately 5H Battery capacity: 300mAh Bluetooth version: Version 5.3 Bluetooth sound processing: equipped with DSP technology and A2DP (Advance Audio Distribution Profile) function Bluetooth frequency: 2.402-2.480GHz Bluetooth transmission distance: Straight line 10M Bluetooth microphone effective distance: 0.5~2M Product weight: 27 grams Product size: 59.6 * 41 * 15mm TF card: supports up to 32G [Optional] Product List: Bluetooth adapter * 1 3.5mm audio cable * 1 Charging cable * 1 Instruction manual * 1 32GB Card *1 Optional