Advanced ergonomic design with thumb scoop encourages natural hand and wrist postures. Mouse angle and height are designed to position the wrist comfortably. Microsoft Track Technology in the mouse gives you precise control on virtually any surface. Windows button for one-touch access to the Start Menu. Power Supply - 2 x AA Batteries Interface - RF Tracking Method - Optical Buttons - 7 Scrolling Capability - 1 x Wheel Color - Black Maximum dpi - 1000 dpi