Ergonomic Vertical Design Made for Left-Handers You can now enjoy our ergonomic vertical mouse design in your LEFT hand! This design provides better support for your forearm,minimizing wrist pain that can come from twisting. Our vertical ergonomic model helps you achieve a more natural grip, better support, and natural wrist position. With our sleek design and added support, the Adesso Wireless Left-handed Vertical Ergonomic Mouse is perfect for long hours of use. 2.4GHz RF Wireless Technology with On/Off Switch This mouse works at any angle with a range of up to 30 ft.with no wires to get tangled. The On/Off switch helps conserve battery power plus the low battery indicator helps you know when it is time to change batteries. Adjustable 3 Level DPI Switch Attain higher precision and better accuracy with your choice of 3 DPI levels. Easily switch from three different DPI levels with the easily-accessible DPI button which lets you quickly switch between the various computer tasks you partake throughout the day. Enhanced Optical Sensor Optical sensor technology improves precision and even lets you work on most glass,wood,marble and leather surfaces without a need of mouse pad.