I purposely used it after 1 beer, then 2, and then 3. I carefully obtained the readings so I know my baseline drinking measures. This device offers the feeling of security BEFORE you get into your car and If you should call for a ride. I make sure I'm 2one hundredths differential before I leave.
Instructions state you can insert mouthpiece "a few centimeters". It actually can only go in a few milimeters. Also, the unit doesn't fit in the case with the mouthpiece inserted; it's not clear whether the unit is designed for constant removal/insertion of the mouthpiece.
Was so happy with the first analyzer I purchased, I purchased 2 more and gave to friends as gifts. To save someone the pain of a DUI or worse, the guilt of injuring an innocent motorist is well worth the investment!
This product is super easy to use! Accurate too!! I studied all my options and found this to be the best deal. And an excellent buy for the price. I'm so glad I got this particular model. Would recommend this to anyone.