Logitech MX Vertical Wireless Mouse Advanced Ergonomic Design Reduces Muscle Strain, Control and Move Content Between 3 Windows and Apple.

ADVANCED ERGONOMIC DESIGN - Places your hand in a natural handshake position using a unique 57-degree angle, preventing forearm twisting and reducing muscular strain by 10 percent (As compared with a traditional non-vertical mouse. Based on Logitech Study, September 2017)