It can be used as signal contact for the control circuit.
Relay with high contact reliability with multiple contacts on one unit.

Smart design means Smart wiring

The integrated terminal covers have an additional benefit in that they act as a guide to improve wiring efficiency but also retain the terminal screw in place: no mislaying the screw, no dropping it or having trouble reinserting it in to the terminal block just fast efficient wiring.
Fast wiring terminals (model name with suffix �gBC�h ) are also available to further improve wiring efficiency, workability and hence productivity.