TopCase White USB Optical Wireless Mouse for Macbook (pro,air) and All Laptop 2.4GHz digital wireless transmission, operation distance is up to 10 meters 800 dpi/1600 dpi, cursor speed adjustable Built-in mouse memory, no recoding is needed after battery replacement The service life of one AA alkaline battery is UP TO SIX MONTHS Ergonomically designed ideally for right-handed