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

Unlike the junk brand I ordered first, this one works.

this shipped really fast worked perfect and was a more heavy duty design than the one it replaced.

Item as listed Worked great.

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.

Just what I needed for my barn roll-up door. Well pleased with all phases of my purchase.

It worked except below 0 is a problem. When its cold swing a stronger magnet across it. That wakes it up.

Its a magnetic switch and it works. What more can I say about it. I am very pleased with it.

I installed two of them on my garage doors in series with my thermostat to turn off the garage heater when the doors are opened. The install was a breeze (used the black and green for n.c.) and they work flawlessly. The pieces seem to be of pretty good quality, and I assume theyll last for years. These are cheaper elsewhere, but without prime shipping.

Does what I needed. Has both normally open and normally closed contacts making it perfect for residential/commercial applications as well as automotive security applications.

Works great if you do better than me and wire it correctly the first time. Thanks to whoever put the following out there: When the door is closed, there is continuity between Black/Green When the door is open, there is continuity between Black/Red