The switch is an electrical switch operated by an applied magnetic field. Designed for use with alarm systems. Embedded in door or window frame, suitable for residential or commercial applications. Ideal for use on windows and doors in homes or businesses. Features double-sided tape for easy installation. and high quality. Switch Type: NC (normally closed type), circuit is connected when magnet is near the switch. Normally closed: When the magnet is close to the switch, the circuit remains closed; when the magnet is removed, the circuit opens. Item Type: Door Sensor Magnetic Switch Model: 38 Material: Plastic Color: White Cable Length: 26cm / 10.24in Rated current: 100mA Rated voltage: 200V DC Operating distance: more than 15mm, less than 25mm Rated power: 3W Connecting mode: NC (normally closed) Package includes: 5 x 38 Wired Door Window Sensor Content limited to the above; other items not included. Note: Lighting and display differences may cause slight color variations between the image and the actual item. Measurement allows an error of +/- 1-3cm.