10pcs Surface Mount Alarm 10W 100V 0.5A in Max Magnetic Contact Ideal for Door Window Security

Minus one star for misleading packaging, but read to end I did make them work. Although the product is labeled "NO" and "NC", it does not directly support both operations.The confusion is different websites mix up what normally open and normally closed means, in reference to the wording here. These switches are open at rest and close when the magnet gets close. Makes sense for an alarm as they are advertised, but I needed closed at rest and open when the magnet gets close.After some experimenting I figured out if you use two magnets, with correct polarity (tricky), on either side of the switch I can get it to work as desired. One magnet fixed, the other moves normal. Makes it a 5 circuit set not 10, but still a good value compared to switches intended to be capable of either operation mode.My use is to turn a small LED light on when a door opens, and shut off when the door closes. Same as a fridge, but without a mechanical switch. Confirmed my prototype before posting.

I wired up 1 of these to a shelly1 relay for automating each of my garage doors. This reed switch provides confirmation that the garage door is actually closed to my hub and the relay on the shelly controls the opener. Because of the space constraints I didn't use the included "other half" magnet side for the 2 garage doors and used some spare rare earth magnets I had laying around to trip the sensor.I use a Hubitat hub and with the Zooz garage opener app everything works amazingly well. Next project is to wire up another building's door and windows in series with 5 more of these switches and connect them to another shelly relay's switch terminal to provide an open/closed notification for the building as a whole. Very economical and reliable compared to using wireless zwave/zigbee/wifi contact sensors for each of these locations.

These are great little magnetic switches. I've bought 30 of them for my hardwired security system. After a total window replacement they all needed to be replaced. In my case there were limited places to locate them, none of which were good candidates for using screws. So I cut the ears off and discarded the cap that covers the wiring screws. It made a cleaner installation when only using the 3M mounting tape. They are secure and every one worked fine out of the box. The magnets are strong and have a great range of operation. Very pleased.

A few of the small magnetic pieces had fallen off the door trim in our house. The main piece of the GE Simon door and window sensor was adhered nicely to the trim, so I used one side of these to replace just the small piece that had fallen off and become lost rather than replacing the entire sensor as a package. Saved a significant amount of money since the sensors are around $40. I still have plenty of these remaining from the 10 pack if any others need replacing in the future.

I recently replaced my house windows and a few of the alarm connectors had gotten damaged. Instead of calling the alarm company to replace the connectors, I elected to complete the task on my own (to save a few dollars). After a few minutes researching the various products, I choose this product. The package arrived on time and installation was a breeze. The connectors also came with double sided tape and screws. I am very pleased with my purchase and would recommend to anyone!

They are exactly what I was looking for and super easy to install. If you're installing them yourself, check with an OHM meter before install. I found 2 out of 10 (20%) were bad. Ain't nothin' like arming your alarm only to have your system say it's not be able to protect that particular opening. Other than that ... good stuff

Replacing the old window sensors after having new windows installed. Very easy to install and works perfectly.

These clip together, but for some reason, they won't always go back together. These are also super huge as far as window contacts go. If you are looking for subtle, these are not the contacts for you. I ditched these and am looking for another product.