Compact SizeThis keyboard is 11.75 Prime; wide and is designed with a Windows layout that includes an embedded numeric keypad. This keyboard is a great space saver for all environments and ideal for public workstation Built-in Optical TrackballThe integrated trackball eliminates the need for a mouse and saves valuable desk space, with its 800 DPI resolution the optical trackball provides superior accuracy and smooth motion requiring minimal hand movement and no maintenance. Quiet Membrane Keys SwitchThe membrane keys offer you fast typing and a lifecycle of more than five million keystrokes.