Fast Response Accurate ResultsAlcohol tester comes with professional airway design and high-precision semiconductor sensor.Digitally displays the concentration result and beeps, accurate and fast reading of the concentration in the blood within 10S. You can get reliable and accurate BAC results. One-button OperationBreathalyzer is allowing you to easily view display results, featuring non-contact mouth blowing, easy to use by pressing the switch and waiting for 10 seconds to warm up.Then use the mouthpiece to blow the tester for 3-10 seconds, and the result will appear in the display. Quick response and accurate result. Clear Screen DisplayThe professional breathalyzer is 3 unit measurement to choice, % BAC, BAC, mg /l. Digital Tester alarms sound when the value is higher than the standard value, designed with a high-definition color display, easy to view measurement values. Built-in 270mAh battery, USB charging, more convenient and quick. Compact PortableThe Breathalyzer with Keychain is compact and portable, and easily fits in a purse or pocket, on a key chain, or in your car. Perfect for you and your family to make alcohol testings, giving you and your family professional accuracy for safe driving. Kindly ReminderThe portable breath alcohol tester has a built-in purification box to filter impurities and accurately detect alcohol content.Usually, the alcohol concentration reaches its maximum after drinking for twenty minutes to half an hour. We recommend waiting 20 minutes after drinking before taking the test. For more accurate results, please wait three minutes between each test.