The black, small EM550GPS Wireless Ergonomic Mouse from 3M is an ergonomic mouse clinically proven to alleviate pain and discomfort of repetitive stress injuries in the hand, wrist, or arm associated with the use of traditional mice. The stress is due to forearm pronation and may cause pressure on the wrist and carpal tunnel area. The mouse is for right-handed users. The ergonomic mouse has earned an Ease-of-Use Commendation from the Arthritis Foundation for its patented, vertical-grip design that keeps your hand and wrist at a neutral angle, while the mouse works as a regular optical mouse. Also included is a pair of AAA batteries for powering the mouse.