1This wine tester uses highly sensitive semiconductor wine sensor. 5 seconds later after blow, you can get a test result to judge whether you can drive or not. 2The portable wine tester comes with a USB cable. You can recharge it by connecting the cable to your car charger or phone charger. 3Noncontact design,you use this wine tester without extra mouthpiece, and your mouth doesn't need to contact the tester to get a result. 4The wideopened wine tester can gather more air you breath out for more accuracy. Please use it 25 minutes after drinking. 5Easy to use, press the power button for 2 seconds to start the professional wine tester, wait for 10 seconds for warmingup, then blow to tester mouth for 35 seconds, the result will be showm within 5 seconds, and then it will be displayed on the LCD screen for 10 seconds. 6Compact size, takes little space, can be easily placed in your wallet or pocket. Great for wedding, parties, feast or other social activities to ensures your safe driving after drinking. 7This newly upgraded portable wine tester uses a new programming calculation method to make the test results more accurate. The test result will be displayed in 2 ways (%BAC and g/l) for easier understanding.