Intelligent LCD DisplayOur alcohol tester has an automatic shutdown function. If there is no operation within 20 seconds, it will automatically shut down to save power. All test results and battery levels are displayed on the LCD screen, and an alarm will be triggered when the battery level is low.Danger Warning The testing range of this personal alcohol tester is 0.00-0.19% BAC (or 0.0-1.9g/l). When the result is equal to or higher than 0.05% BAC (or 0.5g/l), the "Danger" symbol will be displayed on the LCD.Easy to operate Simply insert the 2 * AAA battery, press the switch button for a few seconds to start, preheat in 15 seconds, and then blow air into the alcohol tester for 3-5 seconds to quickly obtain accurate test results. There are 2 units measuring - BAC, g/l.ReminderWhen the tester is not used for a long time, the sensor surface will oxidize, so it is necessary to preheat the product several times before conducting alcohol testing when removing the tester from the packaging for the first time or when the tester is not used for a long time.Highly Accurate BreathalyzerThis alcohol analyzer uses high-precision semiconductor alcohol sensors to monitor your blood alcohol concentration and avoid excessive drinking. To obtain more reliable records, you should undergo testing at least 25 minutes after drinking alcohol.