QWORK MC-31 Wired Surface-Mounted NC Magnetic Door Window Contact Sensor Alarm Reed Switch, White, Pack of 5 with 20 Screws

Ok. Let’s face it that I know nothing about an alarm system. I have an ADT system and a construction worker accidentally broke this small sensor at my basement door. Well after 2 hours of waiting, 4 transfers, and horribly exasperating experience with ADT and so solution. I simply looked on the Amazon for something that looked similar to me and I found this part. The order arrived quickly, it was simple to attach, and it works perfectly. I’m still planning to change from ADT because it’s just terrible.

When our lower level of the house was re-modeled, the contactor did not save the contacts from two door moldings for my Ring and Insteon sensors. I got these just for the contacts and they work fine for my Ring and Insteon open/close sensors.

These are NO, not NC, but that's what you want here. Normally Open, closes when magnet is near. These are direct replacements/copies of the common honeywell sensors. Same dimensions. Bright white matches vinyl windows. I took off a star because one of the five didn't work out of the package, which would be a big deal for someone not familiar with these things, or handy with an ohm meter. Otherwise really great product. I'll buy more as needed.

Terminals didn’t function correctly at first but with a little help they worked fine.

Don’t work with my security system. Not sure what the issue is. Magnet is not able to allow sensor to know door is closed. It is very early to install, but quality is disturbing.

Easy to install. Plug and play.

These units are simple components with a single electric reed switch and two connectors. The plastic containers have no markings, the the hardware used to attach wires is low quality - out of my 5 I had one or two where the screw wouldn't tighten or loosen. Also there's no data-sheet (model name) for the used reed switch. It not known what voltage/current is acceptable but it's common that these units can take 1A or more. I had one take 200mA/9V and I think it blew - it's constantly conducting regardless of magnet. It would be good to know these data to implement using the proper resistors. The mount/case is actually well designed. There's a protective shield that once you mount the active component, there's no easy access to the wires. The magnet has a N/S which again is not marked. You can feel if you're pushing the wrong pole; I recommend making a small mark so when you mount the unit you know the right direction. If you mount a single wire, you can easily get the electronic component exposed by gently yanking on it. This will allow you to change the reed switch if need be, or make other replacements as needed.

They work! They are normally open, not normally closed which is better for my automation products. Switch activation occurs at 1.25 inches from the magnet. Keeping the current very low and not using a super strong magnet should have these switches working a long time.

Does exactly what they’re supposed to do. Used on a security system I pieced together. Works consistently

While I've only gotten one to work so far, I've had 3 duds out of the package as well. Of course the magnet is ok, but the reed switches never closed on those duds.

They are good but I ordered wrong one This one when door are closed they on . So order what you need

Good

I bought it to replace my window contacts for my alarm system. Unfortunately, I had to return the item. The contact overlaps when it is close. I couldn't use it for my application.