HIGH ACCURACY - This alcohol tester adotopted high-precision semiconductor alcohol sensor. It can quickly give a result to judge whether you can drive or not(only 5 seconds). Bring convenience to everyone's life, increase the sense of pleasure and happiness is our driving force. EASY TO USE - Just press the power button for 2 seconds to start the professional breathalyzer, wait for 15 seconds for warming-up, then blow with the tester for 5-6 seconds, the result will be ready after 3 seconds, and it will be displayed on the LCD screen for 15 seconds.(3 AAA battery needed--not included) PORTABLE DESIGN - This breathalyzer alcohol tester is easy to hold and carry. The white cloth bag provides much convenience for you to take it anywhere and anytime, ensures your safe driving after drinking.