1.NO means Normally Open: when the magnet separate, the circuit is conductive( light on );When the magnet together, the circuit is not conductive ( light off ).When make order,please check carefully! 2.NC means Normally Closed: when the magnet separate, the circuit is not conductive( light off );When the magnet together, the circuit is conductive ( light on ).When make order,please check carefully!Note: Door magnetic induction can only provide a switch signal, which can not directly load the power, nor directly connect the lamp!.