Kensington Mouse ProFit Vertical Wireless bkShake 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.