This is the wireless mouse that slips onto a forefinger like a ring for easy control of a computer's functions during presentations. In addition to "left" and "right" mouse buttons, its thumb touch pad uses a patented optical sensor with 1,000-dpi sensitivity, providing eight-way scrolling. It communicates from up to 30' away over an interference-free 2.4 GHz radio frequency with a receiver that plugs into a computer's USB port. Its software works with Windows 7, Vista, and XP. Its rechargeable battery provides up to eight hours of operation from a 30-minute charge using the included USB cable. 1 1/3" L x 1 1/3" W x 1" D. (3 oz.)