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

Was actually a NC contactor for an old school buzzer using 12v. Many others come NO without the three wires.

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

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.

Used in conjunction with a 24VAC relay to turn lights on when garage door opens. Works well. I have purchased my third magnetic switch for indicator light on garage doors (3 doors) this 3rd on I used 120vac through switch to 120vac relay with a 0.3 amp draw. Been on for 4 months and still working well.

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.

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.

Switch can not handle the wattage that it says. First time I hooked it up the reed switch welded itself closed.

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

I bought this to drive a garage door open warning light in my residence. The sensor is designed to be installed on a garage floor, but I chose to install above my rolling door. This meant that the supplied magnet bracket didnt fit, so I built a custom bracket out of sheet metal. Combined with a power supply and blinking LED, I got just what I wanted for less than $30. There are lots of mechanical reed switches available for far less, but I wanted something more robust so Im not replacing it in a year. Im completely satisfied.

This worked great on my new garage door. I use it to indicate if the door is open or closed on my detached garage in the house.