This Both Hands Keyboard has patented Natural-A Shape Keyboard Layout designed to promote a natural hand alignment and posture to help minimise hand, wrist, forearm and shoulder muscle strain. With a standard keyboard the hand does not usually line up well with the forearm which can contribute to Repetitive Strain Injury (RSI). Additionally the Numeric Keypad is positioned on the Left Hand Side to spread the keystrokes more evenly between the Left Hand and Right Hand plus make for a closer mousing position on the right.