6.0 Bluetooth dual-mode dual-channel, compatible with Bluetooth 3.0, 4.0, 5.0, 5.1, 5.3, and 5.4 specifications. Intelligent low-power chip and transceiver provide low-latency, flexible, and powerful Bluetooth applications. Supports Cass2 power level 20 meters (in open air environments) Supports Bluetooth 5.4 dual-mode specifications (LMP 14.5X true Bluetooth 6.0 standard) Supports USB 2.0/3.0 interfaces Supports simultaneous connection of multiple devices (up to 5 devices) Supported operating systems: for 8.1/10/11 (driver-free, plug-and-play); for 7 requires a driver installation. Supported protocols: HFP/ (hands-free phone/headset), A2DP/AVRCP (stereo music), HID/HOGP (keyboard and mouse), AAC, Android smartphones, etc. Bluetooth version: 6.0 (BLE low power, low latency) Transmission range: 20 meters (obstacle-free environments) Supported protocols: A2DP, , AVRCP, HID, AAC, etc. Due to batch variation, product appearance, color, and printing , but this not affect performance. Color:Black Material:plastic Package Contents: 2 * 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.