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

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.

No easy to install with no instructions

Nice unit, solid construction

Worked as described.

Todo bien

Great solution for monitoring garage doors and other roll up doors. I have used these at businesses as well as on moving trucks.

Worked great

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.

worked great.

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