Microsoft WIRELESS OPTICAL DESKTOP. Device interface: RF Wireless. Battery type: AA type(Alkaline). Minimum processor: Intel Pentium - 233 MHz, Processor frequency: 233 MHz, Minimum RAM: 128 MB. Compatibility: PC, Compatible operating systems: Microsoft Windows XP Professional SP1, Microsoft Windows XP Home Edition SP1 Software Included, I/O ports: 1 x USB - 4 PIN USB Type A