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

Works on my DSC system without any problems.

Nice unit, solid construction

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......

Has three wires black is Colin plus one for normally open and one for normally closed . Even without instructions . Hook up black plus one other and see if it signals it closed with the door closed .

Had one installed, but it split in half from winter weather freezing it

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.

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.

Todo bien

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

Needed for a normally open circuit on a gate alarm . Works fine . Just installed so dont know how long it will last but looks well sealed from moisture. Looks like a good product