USB (call version) Bluetooth audio transmitter; Bluetooth version V5.0; Power level Power level 2 (Class II); Audio input interface USB audio input Support voice call Support, Bluetooth headset or speaker needs to have call function. Compatible Support for PC use, support Switch base mode USB transmitter function operation (Refer to the instruction manual for details) On/Off Automatically turn on after connecting the power adapter or computer USB power supply, and automatically turn off after unplugging Button Double-click the button to search and pair again. Long press the button for 6 seconds to clear the pairing record. Function operation 1. Turn on the Bluetooth headset and set it to pairing mode. 2. Insert the device into the power adapter or PC host USB, double-click the pairing button, the LED light flashes quickly, and the device enters the pairing state. 3. The LED light on the device flashes slowly, and the connection is successful. Product name: USB wireless audio transmitter Input port: USB Transmission distance: 8 meters (unobstructed) Frequency range: 2.402GHZ-2.480GHZ Supported protocols: A2DP, AVRCP, HFP Device power supply: USB DC 5V Support: ordinary voice (8K sampling rate, CVSD codec) Support: wideband voice (16K sampling rate and codec) Material:Metal + Plastic colour:black Package Contents: 1 * USB Bluetooth 5.0 adapter 1 * English manual Only the above package content, other products are not included. Note: Light and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.