Magnetic Reed Switch Normally Open and Normally Closed NC NO Magnetic Proximity Switch for Door Alarm, Window Safety, DC 5V 12V 24V Light GPS Other Equipment Reed Switch (White, Pack of 5pcs)

I had replacement windows installed and needed to replace two countersunk magnetic switches with surface mount switches for my hardwired monitored alarm system. Both of these switches didn't work, so I returned them for exchange. Amazon Prime made it quick and easy, and the two replacement switches arrived the next day.The small screw wire connectors aren't the greatest, but they work and the magnets are strong. I had to make a small shim to fit under the magnet that attached to the moveable window to equalize both pieces, a minor inconvenience.My windows are normally closed, so I connected the ground wire (black stripe) to the terminal marked "Ground" and the other wire to the center terminal marked NC (normally closed). That worked, because my keypad status showed a green light.I covered the exposed wires with white silicone for a professional look. Only one window pictured.Recommended.

Works great for my application. Love this thing

Can be wired to be normally open, or normally closed depending on your application. I use these to activate a 12v warning light when a door is opened, but you can use these on security systems to monitor doors and windows. The dual usage (normally open/normally closed) takes the guesswork out of buying reed switches that are pre-determined at the factory to only be one way or the other.

Works as designed

does not work well. contacts are labled wrong -- NO & NC are backwords

Was not the right size for what I needed.

Replaced a broken hall effect sensor on a commercial alarm system. Does it's job day in and day out

Works great