Works great on difficult surfaces like armrests, pant legs, seat cushions and even glass tables ; Terrain Tested Tracking Technology utilizes a blue LED sensor to deliver rock-solid cursor control practically anywhere ; Travel-friendly features include a compact size and convenient storage of the USB nano receiver ; Reliable wireless reception up to 30 ft. ; On/off switch helps conserve batteries ; 1,600 dpi sensor ensures the perfect blend of tracking speed and accuracy ; System requirements: PC with Windows(R) 98/XP/Vista/7, Mac(R) OS X(R) v10.0 or above and available USB port ; Includes USB nano receiver, 1 AAA battery and quick-start guide;