[Very suitable for old motherboards that do not support Bluetooth, plug and play!] Dual mode supports Bluetooth 5.1 low power consumption (backward compatible with 2.0/3.0/4.0), full-speed USB 2.0 interface, conforms to Bluetooth v5.1 specification, 2.402-2.48 GHZ ISM frequency band, low power consumption [Perfect support for Win 8 and above systems. Win 7 installation driver] Class II power standard, distance 0-20 meters, support Bluetooth data rate to 3Mbps [Easy to connect] You can connect a Bluetooth headset from a PC. Unlike a standard Bluetooth adapter, it can transmit audio stably with good sound quality without any obvious delay. This is very important when playing games or watching videos. It supports configuration files: serial port, object push, file transfer, LAN access, personal area network, audio gateway, HID hot group, keyboard, mouse, HCRP (printer cable replacement), Bluetooth low energy , PIM synchronization profile, A2DP, AVRCP. [Support up to 7 devices to work at the same time] Supported devices: Bluetooth headset/Bluetooth keyboard/Bluetooth mouse/Bluetooth speaker/mobile phone/printer/computer/game controller color:Black Material:Metal + plastic Package Contents: 1 x Bluetooth 5.1 receiver transmitter 1 x CD disc 1 x English manual Only the above package content, other products are not included. Note: Light 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.