Features:

• Optical Mouse has a unique ergonomic vertical grip that has been clinically proven to reduce muscle strain and discomfort compared to using a traditional mouse.
• Enhances your comfort by keeping arms and shoulders in a more relaxed, neutral position.
• Right-Handed use and available in small and large sizes so you can find your perfect fit.
• 2 year warranty.
• SOLD BY THE EA

Editor Reviews:

Product Description:
Ergonomic design keeps the arm positioned for natural, comfortable movement. Clinically proven to reduce muscle strain and discomfort associated with Carpal Tunnel Syndrome and repetitive stress injury. Compatible using any USB port computer. Size large.

Rating : - it works
it takes a bit of getting used too, but its well worth the trouble. I should have purchased this thing years ago