Features: 【Sending and receiving in one】This Bluetooth adapter has two receiving functions. The receiving mode refers to an audio playback device connected to a speaker， which receives Bluetooth signals and plays music wirelessly; Transmission mode refers to connecting audio output devices， transmitting Bluetooth signals， and playing music through paired wireless headphones and Bluetooth speakers. 【Car Connection】When used in the car， the car audio system instantly changes to Bluetooth audio， starts with the car， automatically reconnects， can listen to audiobooks， high-definition voice navigation. 【Handsfree Call】 This Bluetooth adapter comes with a built-in microphone for hands-free amplification calls， with clear sound quality and no noise. Product Description: Product name: Bluetooth adapter Product color: black Product material: aluminum alloy Input voltage: 5V Battery capacity: 250mAh Bluetooth version: V5.3 Working distance:10 meters Charging interface: TYPE-C Battery life:13 hours in receiving mode and 6 hours in transmitting mode Supporting protocols: A2DP/AVRCP/HFP/HSP Charging time: approximately 1 hour SINR:>60DB Distortion:＜0.1% Frequency range: 2400MHz -2483.5MHz Frequency response rate: 20Hz-20KHz Left and right head separation: ＞60DB Effective distance of microphone:0-1M Package size:12.9×9×2.4cm/5.1×3.5×0.9in