Tellegloww 20 Sets Nc Wired Surface Mounted Alarm Magnetic Door Alarm Contact Sensor Door Window Reed Switch Sensor with Double Side Tape for Security

Material Quality: crafted from plastic, the surface mounted magnetic door switch alarm sensors is a reliable asset choice for your home security, which ensures longer service life with its sturdiness and resistance
Easy Installation: these surface mounted magnetic alarm contacts come with adhesive tape (no electric wires provided), have no complicated instructions or professional assistance required and can be installed conveniently ( Working current under 12V. )
Extensive Package Content: the package includes 20 sets of window door sensors along with 80 screws supporting the needs of homes, offices, dormitories and even larger establishments such as hotels
Multipurpose Usage: these surface mounted magnet alarms sensors are suitable for a diverse range of utilities, such as doors or windows made of various materials like wood, glass, or plastic in homes, offices, or shops
Operation Principle: NC means normally closed; If the magnet is closed to this switch, the signal is conductive, otherwise, if the magnet is far away from this switch, the signal is disconnected; This working principle is ideal for alarms, LED, door openers, and more