Name: USB Bluetooth 5.4 adapter Bluetooth version: 5.4(BLE low power consumption, low delay) Transmission distance: 20m/150m(in barrier-free environment) Support protocols: A2DP,,AVRCP,HID, etc. 5.3 Bluetooth dual-mode and dual-channel, compatible with Bluetooth 2.0,3.0,4.0,5.0 and 5.1 specifications. Intelligent low-power chip, transceiver, providing lower delay, flexible and powerful Bluetooth application. Support Cass2 Power level 20 meters distance (in open environment) Support Bluetooth 5.3 dual-mode specification (LMP 12.45 real Bluetooth 5.3 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 system can be installed with drivers. Support protocols: HFP/ (hands-free phone/headset) A2DP/ AVRCP (stereo music) HID/HOGP (keyboard and mouse), Android smart phone, etc. Colour:black Material:plastic Note: XP/ Win8/ MacOS system is not supported. Due to different batches, there may be differences in product appearance and printed text, which not affect use Package Contents: 2 x USB 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.