Bluetooth Transmitter/Receiver Product Function Introduction 1. Used for Bluetooth audio transmission in car stereos, older stereos, computers, TVs, and other devices. 2. Supports hands-free calling. 3. Supports Type-C charging. Technical Parameters: Bluetooth Version 5.3 Operating Voltage 5V Bluetooth Transmission Distance 5-10 meters Bluetooth Calling Effective Distance 0.5-2 meters Instructions for Use (Version with RX/TX Switch Buttons) 1. Power Consumption When Off: 67µA, Bluetooth Search Name: M-168 2. Long press to power on or off. Double press to redial. 3. Short press: Previous track, short press: Next track / Long press: Volume up, long press: Volume down. 4. Switch the button to TX for transmit mode; switch the button to RX for receive mode; transmit mode: AUX input stereo; TF card transmit stereo, computer sound card stereo. 5. Receive mode: Blue light flashes when powered on; RGB lights up simultaneously when connected successfully. 6. Transmit mode: Green light flashes when powered on; RGB lights up simultaneously when connected successfully. 7. Red light indicates charging; red light is on when charging, off when fully charged. Color: Black Material: ABS Package Contents: 1 * Adapter