I have had Carbon Monoxide poisoning twice in my life, that I know of. Probably other times I didn't know about. The two times I know of, I had CO detectors to warn me. One of those time, I am certain it saved my families lives.
This is not a joke.
At this price, I just ordered a new one for our home. It's common lore that smoke detector batteries should be replaced yearly. What is NOT common lore is the smoke detectors 'wear out' with age, and CO detectors do so even quicker. I replace detectors every 4-5 years. They are cheap insurance, especially at this price.
My mechanic friends..... if you don't have one of these stuck to the side of your tool box in the shop, you are a fool. I don't mean that in a nice way. Just get one, damn it.
That is all.
Update: It's now Tuesday PM, and I worked a short day. Came home to find the new alarm on my porch.... NEXT DAY delivery. How sweet is that?
It's now installed and tested, and I are pleased.
Now.... anyone need a three year old CO detector for free? I have a spare now. Still works fine.