Differences of NC, NO, NC/NO
Normally Closed(NC): When the switch is close to the magnet, the circuit is conductive(light on); when the switch is separated from the magnet, the circuit is not conductive(light off).
Normally Opened(NO): When the switch is separated from the magnet, the circuit is conductive(light on); When the switch is close to the magnet, the circuit is not conductive(light off).
NC/NO Combined: The switch has 3 contact types: NC/NO/COM, you can choose to connect two of the contacts(NC-COM or NO-COM).

PLEASE NOTE
A magnetic door contact can only provide a switching signal to the device. It cannot directly load the power supply and cannot be directly connected to the lamp.

Specifications:
Model: MC-38
Contact Type: NC
Maximum Sensor Sensitivity: 10-20mm
Load Current: 100mA
Withstand Voltage: DC 0-36V
Working Voltage: DC 0-24V
Mounting Hole Distance: 18mm / 0.71inch
Size(Approx.):
27 x 14 x 8mm / 1.06 x 0.55 x 0.31inch (L*W*H)
Each Wire Length(Approx.): 30cm / 11.8inch
Wire Type: 1007#/24#320mmUL
Housing Material: ABS

Package Content:
5pcs x Magnetic Door Switch
20pcs x Mounting Screws