Review on Hardwired Kidde Smoke & Carbon Monoxide Detector with Lithium Battery Backup - Interconnect Combination Alarm with Voice Alert by Mike Bucher

Installed these alarms in my house and 4 of my apartments to replace old blocks that have become obsolete. Multiple alarms are wirelessly linked to allow simultaneous detection and alerting. A 10-year battery means there will be no battery problems during the alarm's 10-year lifespan if it needs to be replaced. The wireless communication process couldn't be simpler. Turn on the units, press and hold the button on the selected coordinator until you hear a beep. It will then start searching for other devices you want to pair. Upon completion, not only does it give verbal acknowledgment to each block if it is connected, but also gives the coordinator the total number of blocks that are connected.