The Green Power 4 way Professional Contactor timer is great for four light grow rooms with a maximum input load of 4000watt. These units utilise a heavy duty professional contactor and a professional grasslin timer. The 4 Way Contactor timer has a handy built in hanging bracket and can be screwed onto the wall. The back plate is galvanised and riveted on to the unit, two power lead is needed to power the full unit.