Feature:1. NO NC Switch: The magnetic switch has a normally closed function. When the two parts are combined, the switch is turned on, and when they are separated, the switch is turned off. Normally open function is the opposite.2. Application: Magnetic contact sensor switch can be added to existing wired alarm system, suitable for wooden doors or windows, ideal for protecting doors.3. High Sensitivity: The use of high magnetic magnets and reed switches makes the magnetic contact switch more sensitive and efficient.4. Safe Material: The magnetic reed switch adopts ABS engineering fire retardant and flame retardant material, which is safer and more convenient to use.5. Easy Installation: The door magnetic switch adopts surface mount and screw installation method, and the installation is convenient, dependable to use.Specification:Item Type: Magnetic Reed SwitchMaterial: ABS, MagnetScope of Application: Door Frame, Wall, DoorConnection Method: Screw ConnectionOutput Type: Normally Open, Normally Closed (NO/NC)Induction Distance: Approx. 20-30mm / 0.79-1.18inInstallation Method: Surface Mounted, Screw InstallationCurrent Voltage Power: 0.5A 10V 10WSize (One Side): Approx. 55x13x11mm / 2.17x0.51x0.43in.Package List:4 xMagnetic Reed Switch8 x Screw