Microsoft Wireless Optical Desktop 4000 (3.0) Silver PS2/USB Mac/Win Tilt Wheel Technology Smart technology reduces the likelihood of interruption by notifying you when it detects interference or low battery Many users experience a half year of battery life Designed by Microsoft ergonomics experts, the arched shape provides support for your hand in a natural, comfortable position Compatible with Windows XP Professional Edition, XP Home Edition, or 2000 Professional