General Electric 5-wire mechanical latching type relay designed for building automation systems. The relay is rated 20A 120-277VAC SPST operation and requires a momentary 24VAC (21-30VAC) switch circuit pulse to open or close the line-voltage circuit. It may be used to full rated capacity for tungsten filament, ballast or resistive loads. Line-voltage terminals accept copper wire only. This relay can be used to replace earlier discontinued GE models RR4, RR6, RR8, and relays of a similar type by Sierra and Bryant. When replacing these older relays you will need to remove the yellow plastic plug on connector, strip the leads and connect the old red wire to the new red wire, the old black wire to the new black wire, the old yellow wire to the new yellow wire (either) and connect the old blue wire to BOTH the second yellow wire AND the new blue wire.