EASY TO USE Just press the power button for 3-5 seconds to start the professional breathalyzer, wait 15 seconds to warm up, then blow 5-6 seconds with the tester, the result is ready after 3 seconds and it appears on the LCD screen for 15 seconds (3 AAA batteries required - not included).HIGH ACCURACY This alcohol tester has a high-precision semiconductor alcohol sensor. It can provide a quick result to judge whether or not you can drive (just 5 seconds). Bring comfort into everyone's life, increase the feeling of joy and happiness is our driving force.LOUD ALARM SOUNDS You will receive an alarm by emitting a signal tone if the result is higher than 0.050% BAC, 0.500 BAC or 0.250 mg / L (BrAC).PORTABLE DESIGN This breathalyzer is easy to hold and carry. The white cloth pouch offers a lot of convenience so that you can take it with you anywhere and anytime, and ensures a safe driving after drinking.This breathalyzer adopted the blue backlight LCD display, you can read the test results more clearly and conveniently both in the day and at nightincludes1 alcohol tester(This product does not contain batteries)