@Sara952
This is not a monitored system it just like any other fire smoke detector you can purchase at any hardware store for $10....except that it targets cigarette smoke.
Sara, I don't know if Marijuana triggers it, it says it detects cigarette, cigar and pipe smoke, but whether it does or doesn't is not the point.....it doesn't matter. It doesn't matter if it doesn't work at all.....it's there in the ceiling, the specs are posted on the ' No smoking' sign on the wall of the cottage.
As I said nobody has ever put it to the test. I would regularly walk in and detect traces of cigarette smoke as the air filter I have installed was trying to get rid of them but, not once since I have installed that which is almost 2 years now have I smelt smoke in the cottage.
It is worth it for the bluff factor.
Another thing I might mention although not practical for your number of properties but maybe for hosts who list just one property. My cottage has a full filtration system . I have installed a Whirlpool "Whispure 1,000" Hepa air filtration unit which does a great job at filtering allergens from the air and it does (in a reasonable amount of time) get rid of cigarette smoke.
This is basically a portable unit which I have built into the Airbnb conditioning system. The cost is reasonable at less than $200 and it might be something you can have on hand to take to an affected property and scrub the air in a few hours!
https://youtu.be/Z2gt_yJp8d0?t=21
Give it a bit of thought Sara. All the best!
Cheers.......Rob