First Alert CO605 Carbon Monoxide Plug-in Alarm with Battery Backup (3 Pack)

Just received these tonight. They came well packaged, new, no tampering. Each unit came with it's own back up battery. Directions / instruction booklet is thorough, though print is very small, even for someone who's (relatively) young yet.I tested each unit once I installed the barriers & they functioned as expected. They are pretty loud, which is good. Once plugged in the red light glows steadily which is what it's supposed to do. Some people mentioned it being really bright, they aren't.Lastly, please note that the date on the back of the unit is NOT the expiration date! This is the manufactured date (see my photos).I'll update if one of them starts acting up, otherwise I feel good about these & would recommend.

I received the order and installed the batteries in devices. The last one kept beeping and I didn't realize it until I read further, and realized the battery was already old and needed to be replaced. I'm not pleased about that.

I like a 10 year battery with no electric power plug-in.

Easy to set up and very good quality.

We have gas for heating, hot water, cooking, and in our fireplace. Adding detectors down near the floor level where carbon monoxide initially settles is a no-brainer. Finding good places to plug them in that fit with the instructions was a bit challenging in our small place. READ THE INSTALLATION INSTRUCTIONS completely. We sleep better knowing we've got detectors where they need to be, but won't give us "false" alarms by being position too closely to the gas using appliances. Be safe.