product 1.ACCURATE TESTING: This alcohol tester is composed of advanced high-precision nanotechnology sensor, which can accurately feedback your actual situation on top of the LCD display, and can be used with family, friends. 2.PORTABLE BREATHALYZER: The professional breathalyzer is very convenient to carry on the go out and it can easily be put in the bag and car. 3.TIME SAVING AND CONVENIENCE: Environmental protection and energy saving, no need to replace the battery regularly, reduce the pollution of the environment, the device comes with a USB cable allows you to charge in multiple areas, and always observe the power display. Save time cost. 4.EASY TO USE: After you get the product insert the mouthpiece into the mouthpiece insert slot, long press the start button, after the "Beep" sound the product turns on and the screen shows "WAIT" and starts counting down, when the countdown to zero, the screen shows "START", take a deep breath and keep blowing for 5 seconds, then wait a while and the data will be displayed. 5.Good choice for gift givingIt can be used as a New Year gift and Christmas gift for family and friends.