This product is DANGEROUS- it is unreliable and gives false alarms when CO is not present. Additionally, the alarm, which is supposed to be 85 decibels, is painfully loud and cannot be turned off with the reset-test button as specified in the directions. My new unit screamed for nearly an hour outdoors even after I approached it with ear protection to try to silence it with the reset button.DO NOT BUY THIS UNIT AND IF YOU HAVE, I RECOMMEND CONTACTING THE CONSUMER PRODUCT SAFETY COMMISSION. I personally believe that I have ear damage just from my brief exposure to this ear-splitting alarm.