Comfortable shape and materials Enjoy a contoured shape with gently curved sides, broad palm area and soft rubber grips.Extra controls right under your fingers You can do more, faster with Back/Forward buttons, side-to-side scrolling and zoom.2-year battery life With On/Off switch, smart sleep mode and battery life indicator, you might just forget this mouse runs on batteries.Unifying technology - Plug it. Forget it. Add to it. You can connect up to six Unifying devices to this tiny receiver.