THE BEST INVESTMENT YOU COULD EVER MAKE... Protect yourself from driving drunk and ruining your or someone else's life. Know your limit... Quick and accurate test results with a simple one-button operation Electronic airflow sensor to ensure a deep lung sample for testing Temperature sensor displays the temperature at the time of testing with warnings if outside optimal testing range 0.000 - 0.400% BAC (blood alcohol concentration) /- 0.008% BAC sensor accuracy Semicoductor sensor with 4 digit blue backlit LCD for accuracy Includes 9V battery, carrying case, and 5 mouth pieces