MX-2070 3D Wireless Combo Optical Mouse [MS-20-70-WC] is the state-of-art professional Small Wireless Mouse. With the Ergonomic design, MX-2070 is designed to be comfortable and specially fit for your hand position and avoid fatigue after use it for long period. Tranquil-design wheel for scrolling four contact points to reduce resistance and ensure excellent mobility and easy to control on different surfaces. MX-2070 is using AAA battery.