Bests & Worsts Reviews from Amazon

I tested this with my car in the garage. The test button works and makes a sound. Testing with a very old car with no catalytic converter . . . Peak Level reading was 713 PPM and the thing was SILENT the whole time! It should give a series of beeps and alarms after 30 PPM. FACT: At 880 PPM, CO would cause Death within 2 to 3 hours. I understand that sometimes products fail. But not testing their own products speaks to their poor quality control and care for life. Onlly buy this if you want to die from CO poisoning. Rubbish. Pass on this one.