I bought this alarm hoping it would be an upgrade from the EXTREMELY poor-quality Kidde alarms that came with our house (they are supposedly 3 years old but most have already failed catastrophically - they are Kidde 0915 if you are in the same situation). However, the mounting hardware is incompatible with those alarms, so I have to take down the old mounts in order to use my new alarms. This is frankly an enormous pain and makes me think I was a chump to go with Kidde again. I would have picked another, better brand if I hadn't thought I could use the old mounting hardware with the new alarms.I'm still not sure whether I want to return these or not - still deciding - but in any case don't buy these if you already have Kidde detectors in your house and you think sticking with the same brand will make things easier. It won't.