Review on First Alert CO Detector Alarm with Digital Display and Peak Memory, Battery Operated, CO410 - No Outlet Required by Brandon Vox

If like me you used the CO400 front pack with First Alert's old removable AA battery, this new version of the CO410 with display is a direct replacement and also uses AA batteries. First Alert have made changes to the current generation CO400 models, moving the battery compartment with the 9V battery to the rear while increasing the distance between the wall hanging hooks. I already had holes from a previous device so I needed something that was a direct replacement. This version of the CO410 with display is perfect. It was built in July 2019 so it should be around 7 years before it starts beeping. It is hoped that by this time they will be making a similar block for a direct replacement. The display shows how much CO is in the air and ideally you don't have a CO problem, but it's nice to know you're getting a digital reading.