Smart alarm function Reminds you of blood alcohol test results in 3 colours. Green means safe, yellow means warning and red means danger. If the measured value is equal to or higher than the alarm concentration, the electronic breathalyzer lights up a red light and sends a quick prompt tone at the same time. Safe and hygienicThis electronic etilotete does not require lip contact, just blow directly into the air nozzle. You don't need to use a blowtorch (blowtorch can multiply bacteria), which reduces direct contact and makes the test more hygienic. Compact and portable The portable mini alcohol self-test is small enough to easily fit in your pocket, hang on a keychain or keep in your car. Carry it with you everywhere to keep you and your family safe. USB loading The breathalyzer can be easily charged by a USB data cable, and can also be charged by a mobile phone charger or computer USB port. Easy to useplease press and hold the power switch for 2 seconds to turn on the breathalyzer. Ask them to wait 10 seconds to warm up. Blow air for 5-10 seconds, the result will appear in a few seconds and the LED screen will display for 10 seconds.