COSMOS Black Color Privacy Security Wireless Optical Mouse for Apple Macbook Dell Acer Sony HP Toshiba Laptop Desktop Computer - with 'Hidden Windows Key' & 'Lock Screen Key' functions Two security keys to protect your privacy: 1) Press "Hidden key" on the top to minimize open windows to the desktop and mute the sound; 2) Press "Lock Screen Key" on the left side allows you to lock the screen. 2.4 GHz wireless mouse, ideal for home or office use, effective operation distance is up to 10 meters Mouse is compatible with most laptop and desktop computers via USB receiver. It can automactically change to sleep mode when not in use after 5 minutes. Requires 1 x AA batteries (Not included); With a slot at inside bottom to keep the USB receiver for convenience carrying.