Easy to use: simply insert 2 AAA batteries (that the batteries are not included), turn on your breathalyser. Wait 10 seconds to warm it up, and then blow for 3-6 seconds. The result will be displayed later on the LCD screen. The results are displayed for 10 seconds and then automatically switched off.
Auto alarm function: test result is over 0.05% BAC or 0.50‰ BAC or 0.25 mg/L or 50 mg/100 ml, alcohol tester emits a continuous beep and to remind drivers not to drive. (Wait 20 minutes after drinking to perform the test, the result will be more accurate)