This product is a portable alcohol content detector. The core of the instrument uses a semiconductor sensor, which has the advantages of of high sensitivity, high stablity, and accurate detection. The instrument has an LCD display. GUIDELINE: BAC: Blood alcohol concentration refers to the blood alcohol content of the driver is greater than or equal to 0.02@ BAC and less than 0.05% BAC. Drunk Driving: refers to the driving behaviour of the driver whose blood alcohol content is greaer than or equal to 0.05% BAC.