The Safety Interlock Switch is designed for use with an actuator key that has 2 normally open (NO) and 1 normally closed (NC) contacts, as well as a solenoid with 2 normally open (NO) contacts. It features three M20 conduit entries for easy installation. The switch is housed in a durable die-cast housing and head. To lock the switch, it requires +24 VDC power. It comes delivered with a standard key.