Siig JK-WR0G12-S1 , Wireless Optical Mouse , 3 Buttons , 2.4 GHz, Black/Red 2.4GHz wireless technology supports Windows based laptop and desktop computer systems 3-button with scrolling wheel great for web browsing Compact palm size with Nano wireless receiver and built-in storage compartment for ease of carry 1000 DPI optical sensor provides smooth and precise movement Built-in smart power management maximizes battery life