Features Natural Handshake Position Contoured, natural (46.7 degree) slope neutrally positions the wrist, eliminating soft tissue compression. Extended Lip for Little Finger Provides complete support for smoother, larger muscle group movement. Six Button Design Fully-featured mouse with scroll wheel, left, right, forward, back, and DPI (800/1000/1200/1600) buttons. Plug & Play Simply plug in the nano receiver for wireless connectivity up to 20 meters (65.61 feet). Low Battery Indicator Lets you know when it's time to change the battery, so you're never caught off guard. One AA battery lasts up to a year. Nano Receiver Storage Nano receiver conveniently stores inside mouse when not in use. Preferred Mouse in Independent Study In an independent study conducted by professional ergonomists, "users rated the vertical mouse as the most comfortable and that it conformed to their hand naturally." Source: 2019 VSI Risk Management and Ergonomics, Inc. study. Shake hands with your mouse. The Pro Fit® Ergo Vertical Wireless Mouse, with its natural handshake position, improves wrist posture for better comfort. In an independent study conducted by professional ergonomists, "users rated the vertical mouse as the most comfortable and that it conformed to their hand naturally." Source: 2019 VSI Risk Management and Ergonomics, Inc. study. Contoured, natural (46.7 degree) slope keeps the wrist in a neutral handshake position, eliminating soft tissue compression. An extended lip for the little finger provides complete support for smoother, larger muscle group movement. Fully-featured mouse with scroll wheel, left, right, forward, back, and DPI (800/1000/1200/1600) buttons. Simply plug in the nano receiver for plug & play wireless connectivity up to 20 meters (65.61 feet). A low battery indicator let's you know when it's time to change the battery, so you're never caught off guard. One AA battery lasts up to a year. Nano receiver conveniently stores inside mouse when not in use. In an independent study conducted by professional ergonomists "users rated the vertical mouse as the most comfortable and that it conformed to their hand naturally."Source: 2019 VSI Risk Management and Ergonomics, Inc. study.