SM-226L-3Q Seco-Larm Overhead Door Mount N.C. Magnetic Contact w/ 3 Wires for N.O./N.C. Applications (One Pack)

It looks very well made, it was easy to install, and works great so far!

Has three wires black is Colin plus one for normally open and one for normally closed . Even without instructions . Hook up black plus one other and see if it signals it closed with the door closed .

Very well built. I used this to trigger indicator lights on our driveway gate. Both parts mounted to post and gate with no modifications necessary. The included bracket has plenty of mounting options. I was concerned at first that with the gate being steel if it would affect the magnet, it doesnt. Also, the switch does not have to be mounted as close as possible to the magnet, it will work when the components are about 2 inches apart. Had to mount them farther apart than expected and it still worked fine. The only recommendation I would make to the manufacturer is that the recessed areas to mount the switch be enlarged slightly. The recess is too small to get a socket on a hex head screw making it necessary to use Phillips screws.

I have 4. Two can be wired different. Either n/o or n/c depends on which wires you use. They all work great.

I purchased this to replace a cheap unit on a NexxGarage controller. The magnetic range and quality of this unit is great. It can be configured as NO or NC.

This worked great replacing the cheap magnetic contact that came with my nexx home wifi opener. Good quality and solid. Ive been using this for about 6 months now and have no more false readings of my garage door being open when it is not.

worked great.

This is exactly what I needed for my garage door sensor. I had tried a simple reed switch, like one would use on a window, but it just wasnt up to the task. This item is much hardier, and the results are more predictable - meaning no more false readings. I mounted the switch at the top of my overhead door. Because of limited mounting surface on the wall and clearance requirements on the door, I was not able to line up the magnet with the switch. But even with at 50% overlap, it reads correctly. If you are setting up a door sensor that you want to work well for a long time, this is the switch you need.

Very durable. Utilized for double garage doors to detect (open/close) positions. Connected reed switches in series to controller to operate and monitor garage door utilizing WiFi.

10/10 would bang