I bought this product for a festival I went to. transparency I have a Breathalyzer on my car did not want to walk 2.5 miles to my car over and over to check if I was ok to drive. Bought this to save me and my friends from getting a dui it was inaccurate every time it said I was 0.00% and i went to my car and i was actually .11%. Another time it said .08 and my friend was actually .16%. Attaching live result comparison. Be safe and don't drive until you know you are at 0.00% and educate how the body breaks down alcohol to save you and someone else it's not worth it. Coming from experience.