Wireless connectivity options (2.4GHz, Bluetooth 3.0 and Bluetooth 5.0) to accommodate a wide range of computing devices from laptops and desktop PCs to mobile smart devices. Precision tracking on the most difficult surfaces, including glass. AES 128-bit encryption, a triple DPI switch for simple cursor speed transitions, premium quiet buttons. Ambidextrous 3-button design. 2.4 GHz wireless technology, Bluetooth 3.0 or 5.0. Requires 2 "AAA" batteries (included). Grey.