Honeywell 7939WG-WH - Ademco Surface Mount Contacts (White)

Good quality, it’s a little bit pricey

Très bien, mon système d’alarme fonctionne très bien

This sensor replaced crappy sensors that came with Nexx Smart Wifi Gararge. Nexx wanted $20 for a replacement sensor that was no better than the junk they originally shipped. This sensor was only $7 and arrived quickly after ordering. Connected wires, added protective cap (nice touch) then installed in minutes. The sensor comes in two parts that only have to be near each other to register (lots of margin, can even be more than an inch apart!). Now I get proper messages about status of garage door, with easier sensor install than Nexx sensor. Couldn't be happier.

If you need one for old school wire alarm set up, this works really well. No issue. Just a little expensive for something so simple.

These are good contacts for an alarm system, with a sensitivity somewhat greater than others (1-1/2"). While I found that a full 1-1/2" was far too marginal for consistency, an inch was quite acceptable.These were used as replacements when I had new windows installed. The original modules had yellowed, and were sufficiently old that I chose replacement. Mounting was straightforward. Screws and covers are all included. For several, I had to make some 1/4" or 1/2" shims, as the new windows had different geometry than the original windows.I installed one alarm circuit at a time -- typically 3-4 contacts. For those, I taped a magnet to each contact, and queried the alarm system for all closed. This tested my wiring -- any opens would have been noted at this point. Then I installed each magnet for this circuit, and tested again. Finally, I opened each window to confirm the lack of short circuits (which would have prevented an alarm from occurring when the window opened). Following this methodology made the installation straightforward.These have been operating properly for several weeks with no issues. Prior experience indicates that failures are rare for properly installed new devices. I have had 20-year old switches develop intermittent opens, resulting in false alarms (different house), so periodic replacement -- every few decades -- is a good idea, if your technology still requires a wired window contact.