Very mixed feelings about this!
So the quality of the machine is decent all plastic comes with 10 mouth pieces. So i followed the directions to a T. I tried this machine after a hour of drinking some wine just to test it. So when blowing it seems to be a hit or miss but  it does it show the results when it reads. I tried it a few different time while drinking waiting 30 mins in between. Can confirm the results were different. Some times when blowing into the machine its just errors and your have to repeat. The amount that you have to blow kind of feels like its making me sober up after. Overall its a good device to have to be an responsible adult but i don't have a professional machine to compare results. If you had this in your car and someone was really drunk but still saying their good to drive this is just proof that hey your not good to drive your going get a dui.
Rating: 4 stars