Ultra Mini Wireless Portable Mouse. Cordless optical mouse for notebooks makes packing up easy. Mini-receiver docks inside the mouse for easy portability. High Definition optical technology 800 dpi high definition optical technology is 2x more responsive than standard optical mice, works on almost any surface. Soft rubber coating, non-slip rubber coating for comfort and control. Smooth scroll wheel provides better grip for scrolling. Auto power/save mode automatic sleep mode conserves battery life. Power 2 AA Batteries-- not included.