Vertical Mouse 3 Corded A 2200 dpi true optical resolution sensor moves the pointer quickly to reduce hand movements. 5 buttons each programmable with different functions in different applications. For example, a button can be Double Click in one application and Ctrl in another application. A small lip on the bottom edge prevents the little finger from rubbing the desk. The shape has been improved to fit larger hands as well as smaller hands. All 5 buttons are easily operable without contorting your fingers. The button force is light for easy clicking, but still firm enough to avoid accidental actuation.