Perixx 11556 PERIMICE-517 Wired Ergonomic Trackball Mouse, 34mm, Matte and Glossy Trackballs Included, Major Update 2017 Sep Ergonomic design equipped with 1.34" trackball for right hander. Recommended for users with Repetitive Strain Injuries (RSI) symptom and heavy reliance on computer Matte and Glossy Trackballs Included Versatile design - Silent click design with zero noise yet solid rebound feeling, built-in switch for 1000/1600/2000 dpi easy adjustment High mobility - Instead of requesting a fixed space, trackball mouse can sit on only one spot to provide sufficient functions you need. Compatible with Windows 7, 8, and 10; Wired USB Connection