Review on Wireless Interconnected Combination Smoke and Carbon Monoxide Alarm with Voice Location - First Alert SCO501CN-3ST, Battery Operated by Glenn Kumar

I am a volunteer firefighter and I highly recommend these detectors. They communicate with each other wirelessly. So when someone alarms, they all start beeping and tell you which room has an alarm in. I currently have four installed on three floors of my home, one of which is a combination of smoke and carbon monoxide. During installation, you can simply choose the name of the room it belongs to from a pre-programmed list. If one of the detectors goes off, they'll all verbally tell you which room it's in. They also tell you which room has low battery. I had to replace the carbon monoxide alarm after about five years, but that is normal with carbon monoxide alarms as they expire.