Review on High-Precision Handheld Carbon Monoxide Meter | Portable CO Detector | CO Gas Leak Detector and Monitor Tester (1000ppm) by Cyrus Wright

I compared this device to my colleague's $300 device made by Forensics. The cars I work on are often checked for carbon monoxide leaks, and I happened to find one that had a fairly large leak. I put both gauges in the car and watched from the outside while we warmed up the engine and both gauges read the same thing after 20 minutes, but this little cheap gauge responded MUCH faster than the more expensive forensic gauge! I don't know how reliable it is. will change over time and unless I'm in an area where CO can be an issue I would never use it as my only gauge. BUT for the only test I've done with this gauge, this thing seems like an incredible value. The only thing I really don't like is that it took a VERY long time to receive it after ordering and this alarm doesn't come with any vibration or bright lights as part of the alarm. Those things aside, I think it won't be a problem if you use it to check your CO levels at home. You must worry about safety!