The AFC16-04-00-84 is a 4-pole power contactor with all four main poles wired normally closed, controlled by a 110/120 VAC coil rated for 50/60 Hz operation.
All four poles are N.C., so the contactor holds its load circuit closed when the coil is de-energized. That makes it the right fit for fail-closed applications — holding a load active unless a control signal drops the coil out. The 110/120 VAC coil at line frequency means it lands directly on a standard panel control transformer without an extra power supply.