Introducing the Crystal optical mouse with an optical sensor and retractable wire that scans your desktop 1,500 times per second for pinpoint accuracy. Enjoy a mouse that's designed to be comfortable, especially for young children's hands. Small size and full functionality make it perfect for notebook use. Make Overstock.com your choice for electronic and computer gear. Features include: Small size makes travel easier Easy web navigation and scrolling wheel Precision optical sensor Accurate on almost any work surface Advanced design No tracking ball to clean Comfortable for either hand 600-800 dpi optical resolution System requirements: Windows 95/98/Me/NT 4.0/ 2000/XP Mac OS 8.5/9.X Available USB port