Adesso iMouse E20-2.4 GHz RF Wireless Vertical Ergonomic Laser Mouse 2.4 GHz Radio Frequency Wireless Technology This mouse works at any angle with a range of up to 30 ft. with no wires to get tangled. Ergonomic Vertical Design The vertical design provides better support for your forearm minimizing wrist pain that can come from twisting. DPI Switch Button Quickly and easily adjust DPI resolution for a faster response with the convenient DPI Switch located right beside your thumb. Advanced Laser Sensor Advanced Laser Sensor allows greater precision in mouse navigation, increases battery life, and works on more surfaces (such as glassy surfaces) than an optical mouse.