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

This was needed to replace a failed magnet switch which Id bought about a month earlier to make an indicator light for my garage door. I wish Id gone this route the first time. This item is very high quality and was easy to install as it is made for this application.

Not much to say, but its made well, and should last years. As far as wiring, black is common, green is normally open, and red is normally closed. Pretty straight forward...... Well worth twenty bucks......

Works as expected. Used it to automate my garage door with a Raspberry Pi. Now garage door knows position when I give the command to open or close vs just actuate.

This sensor was the perfect choice for sensing when my roll up garage door is completely secured. What I like the most is that this model supports both Normally Closed and Normally Open systems; There are three wires, red/black/green. When the door is closed, there is continuity between Black/Green When the door is open, there is continuity between Black/Red In my application I discarded the red wire and have a raspberry pi send a text notification when the door is opened unexpectedly. The activation range is very good, over two inches. This prevents false alarms when the wind blows against the overheard door and it moves slightly.

Triggers about 2-3 inches away ! Built really well ! worth it $$

MUY BIEN

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.

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.

Using as a sensor with a Raspberry Pi. Working perfectly so far. Straightforward install.

Excellent product. Far better than the run of the mill magnetic switches I first tried. These are very rugged and well made. I highly recommend them.