Adesso IMOUSE E20 iMouse E20 2.4GHz RF Wireless Vertical Ergonomic Laser 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; Ergonomic vertical design provides better support for forearm, minimizing wrist pain that can come from twisting; User can quickly & easily adjust dpi resolution (400dpi/800dpi/1600dpi/3200dpi) with switch located beside thumb; Battery-saving on/off power switch on mouse base can be used to extend battery life & reduce need to change batteries; Advanced laser sensor allows greater precision in mouse navigation, increases battery life & works on more surfaces than an optical mouse;