RF-617A mini Mouse;size: 85*45*28mm; AAA Battery Product Features : 1. Radio frequency 27MHz, enjoy your freely wireless space 2. It has 256 ID code, there is no interference even many mice being used at the same time 3. Automatically save power sleeping functions, battery life be prolonged 4.Systems Compatibility IBM PC and Win 95/98/Me/2000/XP No need driver