First Alert CO410 Digital Carbon Monoxide Detector 3-Pack | Battery Operated Carbon Monoxide Alarm with Digital Display and Peak Memory | Electrochemical Sensor

It was very easy to install these in my house. This is a good value pack for a house with 3 floors.

Easy to install. Seems to be working fine.

Replaced older model. Fit like a glove.

Took around 5 minutes to install. Really easy!!

So I originally bought this SAME exact CO detector/alarm from Amazon back in December 2017. (The little Amazon tag came up telling me when I last purchased it.) I am still using it. It is actually sitting on the chest of drawers in one of my bedrooms. It appears to be working well. I haven't needed to change the batteries yet (in almost 2 years), and it has never alarmed.But I want to share something I learned after purchasing 4 different "retail" CO detector/alarms (so that I had different ones if one didn't work as it was designed). All of these "retail" alarms readily available at most retail brick and mortar stores and online stores (like Amazon), only alarm you once levels are dangerously high (like you need to evacuate the house now, high). They do not show you if you have low levels of CO over many months (which is equally dangerous as ONE high instance). They will again only alarm once it is at the dangerous level.I am NOT saying NOT to get these. Because obviously having a CO alarm is definitely needed ... and this is better than no CO alarm at all. Instead, I am saying if you are looking for a device that MONITORS and displays CO levels as low as 5ppm (versus the 30ppm), I highly recommend the Defender LL6070 Low Level Carbon Monoxide Monitor-Alarm.Because we have older gas heaters, I purchased 2 of the Defender LL6070 Low Level Carbon Monoxide Monitor-Alarms (each one mounted in a hallway close to the heating units). They are significantly more expensive (@ $160/each) and they only have about a 3-year life. However, for those with compromised immune systems, babies, seniors, other health issues, and pets, it is important to know if you have a low-level CO leak. Exposure to low levels of CO over time is also very dangerous. I was told some times when older heating units start to fail, they can start leaking CO. In any case, I feel better having the Defender LL6070 Low Level Carbon Monoxide Monitor-Alarms. I also still have all of the "retail" alarms in each of the bedrooms, because they do serve an important function. I just thought it was important to know that these "retail" devices are only high level CO alarms ... not low level CO monitors.

Seemed like a great product until we installed the batteries. There were no connections to install the batteries to. We sent it back for a full refund. As usual, Amazon honored the replacement and a refund was received in a timely manner. Thank you Amazon.

Essential for home.

Replaced older similar unit in my condo. AA batteries are easier to replace than prior 9v battery; battery monitor is visible at all times; extra feature to display recent C/O level history is very valuable for learning of low level C/O existence.

Flimsy battery cover that broke on the first day. It’s also not been reading stuff.