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

Very high quality alarm contact with an all metal body and nice metal wrapped cable. I’ve used many of these in my past job and never had one fail in and industrial or residential application. It’s definitely one of the highest quality alarm components I’ve encountered. I would recommend it to anyone who wants a rugged contact. I’ve paired them with the dry contacts on Honeywell wireless sensors to create a wireless option as well.

So, 5 stars for quality, but yikes, $20 for a magnet sensor, so 4 stars for value. Anyway, I bought a Nexx garage door wifi control which is just a repurposed $5 Sonoff control with a very cheap magnetic sensor for reporting door position, but it also has a fairly good app (so you pay for the app I guess). Read the reviews on the Nexx, a large number talk about it working and then not, becaue the position sensor stops reporting correctly. and thats because It needs an 1/8 gap on a garage door. On my wobbly old door youre never going to get that consistency; so Sentrol to the rescue with their 2 inch gap. This sensor is industrial quality. Buy a LeMotech ABS Plastic Dustproof Waterproof IP55 Junction Box, cut the cord on the cheap magnet, and splice it into the Sentrol inside this box. Two day shipping, problem solved. Oh, and use the black and green wires from the Sentrol for this application.

replaced a 30 year old alarm switch on the garage. Its 1/2 the size and works well.

Item as listed Worked great.

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

No easy to install with no instructions

Nice unit, solid construction

Great product and I will definitely buy it again because there is no alternatives.

Worked great

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.