Review on White Hardwired Smoke Detector BRK 7010B with Photoelectric Sensor and Battery Backup by First Alert by John Castle

Do not do this if you want to be woken up at midnight. I've bought several of these. On the 2nd day I installed them. One of them briefly walked away around midnight and stopped. There was no smoke at all but the siren sounded so loud it woke everyone up. The problem is you don't know which one worked. There should be a flashing red light to tell you which one has failed, but none of them showed a red flashing light. I then returned the one I suspect most to Revane. Just yesterday around 11pm one of them turned back on, lasted about a minute and stopped. Another false alarm and everyone was awakened again. However, none of them had a flashing light, so I couldn't figure out which one was off. I had to delete them all. Obviously these alarm clocks have some quality issues. Shame on you, First Alert. You just had no idea how much trouble your product was causing our family when it mistakenly went off at midnight, waking the kids up.