Fast Response Accurate ResultsThis professional breathalyzer uses semiconductor sensors to accurately and quickly measure BAC levels to ensure safe driving. Small and light, it is your safe companion for home travel and party drinking. Easy to UseNotwith3x AAA batteries is included. Just need to press the button for 1 second to start, and 15 seconds to warm up, then blow to the alcohol breath tester for at least 5s, and will get real-time answers within 3 seconds. Three units of measurement can fully meet your needs. Hygienic MouthpiecesThe alcohol breathalyzer is equipped with reusable mouthpieces. The mouthpieces can be cleaned and recycled. 5mouthpieces can meet the needs of you and your friends and family at the same time without worrying about hygiene. Compact PortableThis breathalyzer is small in size and light in weight, suitable for carrying in the car or in a bag. In addition, we also have a storage bag that fits the breathalyzer and mouthpiece perfectly, making it very convenient to carry so that you can easily check BAC levels anywhere and anytime. Kindly ReminderUsually, 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.