Make sure this fitsby entering your model number. Switch Type: NC (Normal closed type) This Contact Works with Any Access Control or Burglar Alarm System Available This contact can't connect directly to power, it works with your alarm system provide a switch signal. Working current under 12V Great for use in family and factory window, door. etc. NC means Normally Closed: When the magnet together, the circuit is conductive (light on); When the magnet separate, the circuit is not conductive (light off).