85A Normally Open contacts, spst, One circuit: Off - On Housing: Plated steel. Studs: large copper studs 5/16" -24 thread, hexnuts and lockwashers included. Coil, ignition and ground terminal: Steel 10-32 thread, hexnut and lockwasher included. Bracket mounting holes 5/16" x 19/32" (7.9 x 15.1) on 2 13/64" centers (56.0mm).