Safety sensor switches are used in machines and other industrial applications to prevent accidental contact with live electrical connections. Safety sensor switches work together with hinged, sliding, or lift-off guards and barriers. The power supply to the machine is disconnected as soon as the guard is opened. Safety sensor switches include safety interlock switches, limit switches, and cable-pull limit switches. These safety sensor switches are available with a wide range of actuators, switch types, voltage and ampere ratings, contact materials, and termination types. A safety sensor switch can be used on machinery gates or doors guards where key removal brings the machine to a safe condition either immediately or at a pre-determined interval. The most common types of safety sensor switches are break-a-beam switches, interlocks, and tag out devices, perimeter guards, photoelectric safety sensors, safety blocks, safety interlock switches, and wireless safety. Safety sensor switches provide readily accessible emergency stop over a long linear distance such as exposed conveyor lines.