5.4 Bluetooth dual mode dual channel, compatible with Bluetooth 2.0, 3.0, 4.0, 5.0, 5.1 and 5.3 specifications. Intelligent low-power chips and radio frequency transceivers provide flexible and powerful Bluetooth applications with lower latency Support Cass2 Power level 20 meters distance (in open environment) Supported operating systems: Windows 8.1, 10, 11 (driver-free, plug and play) Windows 7 can be installed with drivers. Supported protocols: HFP or (hands-free phone or headphone) A2DP or AVRCP (stereo music) HID or HOGP (keyboard and mouse) or ACC. Android smartphones, etc. Bluetooth version:5.4 (BLE low power consumption, low latency) Transmission distance:20 meters (barrier-free environment) Support protocols:A2DP, , AVRCP, HID, ACC, etc. Support USB2.0 or 3.0 interface Supports simultaneous connection of multiple devices (up to 7 devices can be connected) Working temperature -20 to 70 Colour:Black Material:ABS Package Contents: 1 x USB Bluetooth 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. Note: Due to the light and screen setting difference, the item's color may be slightly different from the pictures. Please allow slight dimension difference due to different manual measurement.