This pressure-activated ignition kill switch installs directly into the front brake line. When brake line pressure exceeds the normal operating range, an internal switch opens to shut off the ignition power supply. Pressure can be adjusted to operate with most braking systems between 500 and 1200 psi and switch pressure set 150 to 200 psi above normal. The switch will reclose and charge the ignition when pressure is released, and then the engine will refire. In the case of a stuck throttle, this switch can provide extra time for the driver to slow the car, shut off the master disconnect switch, and take the car out of gear or "unstick" the throttle. A driver's first reaction to a stuck throttle is to apply the brakes; drivers don't have time to look for switches/buttons mounted elsewhere in the vehicle when trying to control it.