It feels cheap, the results are wildly inaccurate or simply don't work. I just got done RMA'ing the second one. I have a $600 one I brought home from work that is calibrated on a monthly basis and is dead on accurate for comparison. A twister game spinner would be more accurate at detecting blood alcohol content. It is kind of scary when someone that you know is over 0.08, and this product shows 0.00%. A one star rating is one star too many.