Cosmos Star Series Glossy Turquoise Blue Color USB 2.4ghz Cordless Wireless Optical Mouse for Apple Macbook Dell Acer Sony Hp Toshiba Laptop Desktop Computer Contoured shape ideal for left & right hand users Requires 2 x AAA batteries (Not included); Push the button which is on the bottom Effective operation distance is up to 10 meters With scrolling button, 2 level DPI switch USB receiver can be stored inside the mouse when not in use