3M Mouse Ergonomic Optical EM550GPL Wireless Black LargeVertical grip ergonomic design keeps your arm positioned for natural, comfortable movement. Clinically proven to reduce muscle strain and discomfort associated with Carpal Tunnel Syndrome and repetitive stress injury. Wireless. USB Plug and Play. For larger hands. It may feel a little different at first, but before you know it you'll begin to feel the benefits of using a mouse that truly displays Ergonomic design at its best. For right handed use only.