The RollerMouse PRO3 Ergonomic Mouse sits in front of your keyboard, rather than sitting to the left or right like a traditional mouse. The main benefit that this provides ergnomically is that it eliminates the need to reach for your mouse, which can cause stress in your wrists, arms, shoulders and neck. The cursor is controlled by the Rollerbar, which can be used ambidextrously. The mouse has 6 programmable buttons and is compatible with both OSX and Windows.