Handshoe Mouse allows your hand and fingers to relax while mousing, helping to reduce the risk of repetitive stress injuries (RSI). Sculpted design fully supports hand and wrist with negative inclination, which prevents wrist extension. Supports both the thumb and the fifth finger so that neither drags on mousing surface. Laser sensor. Black.
Two buttons with scroll wheel (three on the large model) • Plug-and-play • USB • Compatible with Windows 95/98/ME/2000/XP, Vista, 7, Mac OS 9, Mac OS X, and UNIX • 3-year warranty on Light Click models
Sizing: Measure from wrist to tip of ring finger.
Small: up to 7"
Medium: 7" to 7-1/2"
Large: 7-1/2" to 8-1/4"
More information: http://www.alimed.com/handshoe-mouse-22971.html