Description: Product Name: V5.1 Bluetooth Adapter; Interface: USB 2.0; Transmission rate: maximum 10Mbps; Bluetooth-compatible version: Bluetooth-compatible V5.1; Frequency band: 2.400-2.480GHz; Colour: Black; Product size: 21 x 16 x 5mm; Low-power options: 1.2 to 3.6 VI/O; Compatible with Bluetooth-compatible: v1.2/2.0/2.1/3.0/4.0; Supported operating systems: compatible for Windows, Android, Linux, FRERTOS, ThreadX UITRON; Support software: compatible for Microsoft Bluetooth-compatible software, CSR Har mony, Bluez, Bluesol; Support application functions: HFP/HSP (hands-free phone/headphone) A2DP/AVRCP (stereo music) HID/HOGP (keyboard mouse). DUN/PAN (online), PBAPMA; PFTPSPP.GATT, etc.; Packing list: 1 x Bluetooth Adapter Note: 1. Due to manual measurement, please allow 1-3cm error. Make sure you don't mind before bidding. 2. Due to the difference of different monitors, the picture may not reflect the actual color of the product. Thanks.