Limit switches obstruct the passage of an object beyond a predetermined point. These switches are triggered by the very motion of the object they block. Limit switches contain a switch body with the electrical contact mechanism, an actuator that comes into contact with the target object, and the receptacle or terminals, with screws required for wiring. The working of the limit switch depends on the type of actuator and the lever used, and the choice of output configuration. Most limit switches use snap action for contact, but some models have a slow, make-break action. Of the various models of limit switches, standard industrial oil-tight switches are very robust, capable of withstanding shocks and vibration, and are best suited for industrial environments. These models usually have a modular construction. Precision switches and miniature switches are smaller in size and cost less. Limit switches find widespread use owing to the high levels of reliability and accuracy. The switch can trigger its action repeatedly, and consume very little electricity. Most limit switches can switch loads with high inductance, and control multiple loads. Some of the common accessories for limit switches include roller levers, roller cranks, roller tappets, wing handles, spring-loaded rods, spoon levers, turning levers and more, each aiding the operation of the switch.