A switch and interface in one. Simply plug this 2 ½-inch diameter switch
into any USB port on your computer and press to simulate a left mouse
click, while maintaining full access to your keyboard and mouse. Switch
Click USB features an external switch jack to accommodate the switch of
your choice. Also new for 2010 - simple adjustments allow it to send
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. (Requires purchase of a second Switch Click USB).