It works exactly as expected. I have had this alarm for two years already and I needed to add another detector. Flawless operation and fully customizable.

If you're going to buy it, don't expect much. It works, but only if you have it at a high level. If you set it at a low level, it takes a long time to give the signal because it doesn't read well. I have 2, one from the starter kit and the other I bought separately. If you asked me if I would buy it again, I would say no and I would give a chance to the Ajax curtain or the plus model, maybe they save it with the infrared.