Photoelectric sensor - best for detecting slow smouldering fires.

Please see the trouble shooting guide below if you are experiencing false alarms with these smoke alarms.
 
Extra loud warning tone - 85db at 3m
Low battery warning - alarm chirps intermittently
Large Hush/Test button - easy to test and quieten nuisance alarms
Battery operated - 9V battery included
Easily installed - all mounting hardware included.
Meets NZ Building Code