12V time-delay relay. Time delay is 10 +/- 2 seconds. Pin 30 - +12V supply (Positive) Pin 85 - Ground (Negative) Pin 86 - +12V Trigger (signal to activate the relay) Pin 87 - Normally Open (NO), +12V connected here after delay Pin 87a - Normally Closed (NC), +12V here when no trigger voltage is present. When trigger goes high, this pin goes low after delay. Nominal operating voltage 12VDC. 11-14 VDC range.