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/HSP (hands-free phone/headphone) A2DP/ AVRCP (stereo music) HID/HOGP (keyboard and mouse)/ACC. Android smartphones, etc. Bluetooth version: 5.4 (BLE low power consumption, low latency) Transmission distance: 20 meters (barrier-free environment) Support protocols: A2DP, HSP, AVRCP, HID, ACC, etc. Support USB2.0/3.0 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: 1x 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.