The Bluetooth transmitter makes everything Bluetooth-enabled, lets you enjoy the fun of wireless, and can be paired with Bluetooth receivers (such as 2 headsets) simultaneously. Turn on the switch, the A / B blue light flashes, after the connection is successful, the blue light is always on, and the working status can be seen at a glance. This Bluetooth audio adapter makes your and other Bluetooth-enabled devices stream audio to your Bluetooth headphones. Low latency for clear fidelity stereo sound, lag-free content streaming in streamer mode, giving you a richer and sound experience. Plug and play. With a built-in 300mAh rechargeable battery, it only takes 1-2 hours to fully charge and runs for 6 hours. Name: Bluetooth adapter Bluetooth version: Bluetooth V5.0 Working frequency 2.402G -2.480G Charging voltage: DC 5V Bluetooth protocol: 5.0 , A2DP, , AVRCP Bluetooth compatible distance: 10m (open area) Output connection mode: AUX 3.5mm Material:plastic colour:black Package Contents: 3 x Bluetooth Audio Transmitter 3 x 3.5mm Aux Cable 3 x USB Charging Cable Only the above package content, other products are not included. Note: Light reflection 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.