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

I have 2 of these installed on garage doors, unheated space for many years and they have never failed in harsh MN weather, that is why I purchased 2 more for barn doors on a new building.

Buy this one instead of the Honeywell Contacts because this one have contacts for both Normally Open (NO) and Normally Closed (NC) circuits so I use one for my alarm and another circuit for indicator for the garage doors are open or closed. There are no label the wires so you need to test it with test meter. Need to connect to a relay if pull more amperage or volts. The distances apart can be up to 2 inches.

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.

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

Extremely good quality. This is a robustly built product. I have two in service. Installed with no issues. Flawless operation. Good range of detection l, which eases installation.

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

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.

No easy to install with no instructions

Work great I used it outside as a gate n/c contact when the gate open a bell ring

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