Review on 🔥 2-in-1 Natural Gas and Carbon Monoxide Detector: Reliable Plug-in Co Detector for Kitchen/Home, UL2034 Certified by Craig Pham

DO NOT INSERT BATTERY! As other reviewers have noted, installing a 9 volt battery according to the instructions causes the device to overheat, make a loud popping noise, start smoking, and beep constantly. Removing the battery seems to fix the problem, but now you only have the alarm when the device is on. I bought two for two different parts of the house and they both did the same thing. It's a damn fire hazard! Cheap junk "Made in China".