Instruct: Classify Amazon reviews into positive or negative sentiment
Query: I'm not even sure it's workng

It does NOT constantly display the CO level in the room as the article states. The only thing that makes me think it's even working is the power light, which is not very bright. I gave this a rating of 2 stars because the main reason I bought this model was because the article says that it displays the CO level all of the time. It doesn't so what use is it? Will it work in an emergency? I don't really know.