7-BUTTON ERGO MOUSE - Wired ergonomic trackball mouse with quiet clicks (left/ right/ backward/ forward/DPI switches) and they work with the trackball simultaneously Easy to switch the cursor speed with DPI switch buttons (resolution 400/1000) NATURAL ERGO DESIGN - The ergonomic trackball mouse is for right-handed users recommended to repetitive strain injuries RSI users and the users work particularly long periods on the computer e g office worker gamer and internet user The mouse helps to prevent fatigue in arms and tennis elbow