Quick response accurate results: This professional breathalyzer uses solid-state sensors to accurately and quickly measure blood alcohol levels to ensure safe driving. Small and lightweight, it's your safe companion for house trips and parties. Easy to use: Not with 3 AAA batteries included. Just press the button for 1 second to start and 15 seconds to warm up, then blow on the breathalyzer for at least 5 seconds and get real-time responses within 3 seconds. Three measurement units can fully meet your needs. Hygienic Tips: The breathalyzer is equipped with reusable tips. Mouthpieces can be cleaned and recycled. 5 mouthpieces can meet the needs of you, your friends and family at the same time without worrying about hygiene. In addition, we also have a storage bag that fits the breathalyzer and mouthpiece perfectly, making it very convenient to carry around so you can easily check blood alcohol levels anywhere and anytime. Kind Reminder:Usually the alcohol concentration peaks after drinking for twenty minutes to half an hour. We recommend waiting 20 minutes after drinking before taking the test. For the most accurate results, please wait three minutes between each test.