High precision mechanism design offering acute operation and long life. Its a really usefull switch, for DIY projects. Features with Hinge Lever Actuator, 1NO+1NC Conatact Congfiguration, 3 Terminals design. In snap action contacts, the movement of the actuator applies force to an overcenter mechanism. This mechanism creates a quick change in contact state when the trip point is reached. Reversing the motion of the actuator to a given reset point causes the contacts to snap back to their original position.