Specification:Description:Suitable to used in apartment, hotel, office, etcThe Entry Alarm adopts magnetic sensor design to detect any entry from door or window.Easy to install, it will warning you somebody is coming in with loudly and harsh sound.Switch Type: 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 ).
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