2.4GHz radio frequency wireless technology works up to 30ft; Ergonomic gel surface conforms to hands curves to reduce stress & bring comfort; Optical sensor technology keeps the device precisely on point & lets user work on most glass, wood, marble & leather surfaces without a mouse pad; 800dpi resolution is ideal for precise control & navigation; Battery-saving on/off power switch on mouse base can be used to extend battery life & reduce the need to change batteries; Black;