The following smoke detector works also very good. Once you thaught them to speak to each other, you can also grab that signal when you discover for new devices.
You can read the signal if one detector starts the alarm or send that signal via pimatic, which makes them good alarm sirens if someone is at your door when you’re not at home.
Only thing is, batteries tend to get low very fast, I guess I have to change them every 3 months. Let’s see what eneloops can do
So far I never had false alarms (I own four of them) as despricted in the reviews at amazon
https://www.amazon.de/gp/product/B00GJV48OI/ref=oh_aui_search_detailpage?ie=UTF8&psc=1
Brand: Flamingo
model: FA21RF
type: alarm2