Pressing the 2.5-in/6.35-cm switch top of the Switch Click USB simulates a left mouse click while maintaining full access to your keyboard and mouse. Features an external switch jack for use of your choice of switch. Add a second switch you and use it for simple adjustments such as Left Click, Right Click, Space, Enter, Tab, and Arrow keys: Up, Down, Left and Right. Now you can have full access to two-switch scanning, any way you like.