Bests & Worsts Reviews from Amazon

This is the worst $50 I've ever spent. I HATE this alarm. Although it's plugged into the wall, you also _have_ to install a 9 volt battery. Most devices that have a battery back up don't drain the battery while the unit is plugged in. Not this alarm! I probably go through 3-4 9 volt batteries each winter. And if the battery starts to lose it's charge, or you dare to leave the battery out, the alarm beeps every few minutes. Another important thing to note about this alarm... although it can detect carbon monoxide and natural gas, you're supposed to mount the device at different heights depending on the gas you're trying to detect. In other words, it doesn't really serve it's dual purpose. Although I've already lost the $50, I'll be buying a different alarm for this season. I can't take dealing with its battery problems anymore.