“I've bought three of these. The first, bought more than a year ago, continues to work great. I bought two more last Christmas to give to my sons. One of them worked for a week and the other worked about a month. While I was very disappointed by that, the first one works well enough that I'm still giving it 3 stars. If it works, it's a phenomenal value for the money.”
“works great for me! But how do you calibrate one?! I use it daily bc I have a breathalizer in my car...i heard you need to calibrate it once a month if you use it daily like I do.”
