Easy to understand and easy to install. These detectors make sense since they will all activate when one goes into alarm. So the basement detector will be heard in the bedroom, or wherever you place the alarms. I installed six in less than 90 minutes. I highly recommend these. Ten year battery means no periodic changes. I heavily researched these interconnect alarms prior to my purchase, these are the ones you want in your home.
I moved into an older home with older battery operated smoke alarms. My kids will sleep through anything and these smoke alarms let me
know when any of them go off because they are wirelessly connected to each other . No internet needed