Having 3 pairs of such equipment, including 2 for family and second home I put in reserve future installation. The first pair installed seemed OK for 3 weeks, then unjustified alarm, then back on Amazon in 1 month OK. Wanting to then test the other devices in reserve, the same problem occurs when the installation is made without any hallway smoke exposure (no kitchen or fireplace or smoking). I feel sorry for people too old or semi valid that meet the squealer alarm problem without being able to stop it! To top it off, after 1 month, Amazon no longer uses the same equipment if there is a formal defect, Amazon thank you !!!! :(
