Gear Head 2.4 GHz Wireless Optical Nano Mouse, Piano Black (MP2325BLK) Optical Sensing Technology 2.4 GHz Wireless Connectivity Automatic Wireless Synchronization Scalable DPI Built-in Scroll Wheel Optical Sensing Technology 2.4 GHz Wireless Connectivity Automatic Wireless Synchronization Scalable DPI Built-in Scroll Wheel Storable Nano Receiver PC & MAC Compatibles Mac OS 10.3 and above