Intelligent low-power chip, RF transceiver, providing lower delay, flexible and powerful Bluetooth application. Support Cass2 Power level 20 meters distance (in open environment) Support Bluetooth 5.4 dual-mode specification (LMP 13.X true Bluetooth 5.4 standard) Support USB2.0/3.0 interface. Support multiple devices to connect at the same time (up to 7 devices can be connected) Working temperature -20 to 70 support: 8.1, 10, 11 (driver-free, plug and play) windows7 installation drivers can be used. Support protocols: HFP/ (hands-free phone/headset) A2DP/ AVRCP (stereo music) HID/HOGP (keyboard and mouse) /ACC. Android smart phone, etc. Note: Win8.1/10/11 driver-free, plug and play, Win 7 need to install drivers. This product is not supported on for-MacOS/IOS system. Blutooth 5.4 adapter 5.4 Bluetooth, dual-mode and dual-channel, Compatible with Bluetooth 2.0, 3.0, 4.0, 5.0, 5.1 and 5.3 specifications. Colour:Black Material:ABS+Metal Package Contents: 1 x Bluetooth 5.4 Adapter 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.