Features: The latest Bluetooth-compatible 5.3 technology has made major breakthrough, optimizing the transmissiondelay and connection defects of the old version of Bluetooth-compatible5.0 USB Bluetooth-compatible 5.3 Adapter support downward compatible-bluetooth 2.0/3.0/4.0/5.0-/5.1 devices. Diver-free for Win8.1 and Later ;Only use on Windows- computer Bluetooth-compatible 5.3 high performance and stable transmission, durable. Plug play- it can connect 5 devices at the same time-. Specifications: Item: Usb Bluetooth-compatible 5.3 Receiver for: computer laptop wireless keyboard mouse and more Color: Blue/Red Material: Plastic+Metal Size: approx 3.4x1.8x0.8cm/1.34x0.71x0.31 Quantity: 1PC Package Includes: 1 Piece Usb Receiver note: Due to the problems of lighting effects and shooting angles, there will be certain tolerances in the product, please understand. Please allow 0-1cm error due to the manual measurment.