Hinge Switch, Rotacam, No Special Features, 2 N.C. Safety, 1 N.O Aux, 2 N.C. Safety Contacts, Break Before Make, 1 N.O. Auxillary Contact, Hollow Hinge Shaft 30mmx16mm, M20 Conduit, 1/2in. NPT adptr, Hinge Switch, Die Cast Alloy (red)Hinge Switch - Rotacam: Contacts: (Safety/Aux) 2 Normally Closed / 1 Normally Open, BBM Preference: Break Before Make, Actuator Shaft: Length: 30MM Diameter: 16MM-Pre-Bored, Conduit Entry: M20 Conduit 1/2in Adaptor