This device provides accurate BAC with readings clearly on a LCD display. It features 10s countdown to get ready to test and 5s response time. In use, different symbols get presented on display for instruction like warm-up symbol, blow symbol, low battery symbol, power-off symbol which makes every step easy. And it alerts you when your BAC level is 0.02% BAC(or 0.2g/l) to 0.05% BAC(or 0.5g/l) by showing a Caution symbol on display, it beeps and shows a Danger symbol on display when your BAC level is equal & over 0.05% BAC(or 0.5g/l). The device will turn off about 35 seconds after the result is displayed to save energy which means even 2 AAA batteries can run for a very long time. Compact and lightweight design Digital LCD display shows clear texts 10s warm up time and less than 5s response time Different symbols indicted on display for easy operation Caution alert shows on display when alcohol concentration level is 0.02% BAC(or 0.2g/l) to 0.05% BAC(or 0.5g/l) Danger alert beeps when alcohol concentration level is equal & over 0.05% BAC(or 0.5g/l) Low battery indication Auto power-off With a hand harness Runs on 2 AAA batteries (not included) Sensor: advanced semiconductor oxide alcohol sensor Range: 0.00%-0.19% BAC (0.0-1.9g/l or 0.00-0.95mg/l BRAC) Power input: 2 X 1.5V "AAA" alkaline batteries Operating time: warm up: 10s, response: <5s Auto power off: 35 seconds approx. Dimension: 3.78”×1.42”×0.71”9.6×3.6×1.8cm（L×W×H） Weight: 0.69oz/19.6g Package size: 11×8×2.49cm（L×W×H） Package weight: 36.85g 1 × Digital Display Alcohol Breath Tester 1 × Hand Harness 1 × User Manual