The Tapmaster Model 1720 cabinet door activator is our simplest and most invisible faucet activation system. The activation button hides behind the cabinet door or drawer face and is triggered by gently pressing your knee or thigh up against the front of the cabinet. The button only moves 0.5mm (0.02″) which means it doesn’t cause your door to stick out. By installing the button on the seam between the left and right doors, you can use either one to activate the water flow!