Adesso IMOUSE E10 iMouse E10 2.4GHz RF Wireless Vertical Ergonomic Mouse 2.4GHz radio frequency wireless technology; Works at any angle with a range of up to 30ft with no wires to get tangled; On/off switch helps conserve battery power; Vertical design provides better support for forearm, minimizing wrist pain that can come from twisting; Back & forward Internet navigational buttons are conveniently located on the left side of mouse to provide Internet browser control with minimal hand movement; User can quickly & easily adjust dpi resolution (1000dpi/1500dpi/2000dpi) with switch located beside thumb;