High-AccuracyThis alcohol breathalyzer adopted a high-precision semiconductor alcohol sensor, can real-time response and resume, minimize the mistakes; with three kinds of unit conversion( % BAC/BAC/mg/L) Portable Design Space-saving, lightweight, portable, easy to hold and carry, can put it on your bag or pocket, stay with your when driving; great for wedding, parties, or other activities, ensures your safe driving 5 Mouthpieces Replace Comes with 5 replaceable mouthpieces, maintain health and hygiene alcohol test; with one mouthpiece has been install to the breath inhaler, no worry to forget to carry it Easy to Use Warm up for 15 seconds and blow into the breath inhaler for 3-5 seconds, then read the text result from the alcohol tester LCD screen; the result will display about 20 seconds and then will automatically switch off