Real-time Response This alcohol tester 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, , 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 drivingReplace Comes with 5 replaceable mouthpieces, maintain health and alcohol test; with one mouthpiece has been installed, no worry to forget to carry it anymoreEasy to Use for 15 seconds and blow 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 offDescription: With this digital breath alcohol tester, promptly and conveniently design for measuring BAC, a simple to analyze blood alcohol concentration at any time and anywhere.How to Use:1. Press and hold the power button for 1 second, the alcohol tester LCD with turn on with one beep sound.2. Warm-up mode countdown for 15 seconds.3. Testing mode countdown from 10 to 00 after warm-up mode, blow at this period.4. Blow for 3-5 seconds with normal power after a deep inhalation.5. Read the test result from the alcohol tester LCD.6. The "Caution" symbol is displayed at: 0.020%BAC to 0.50%BAC; 0.200BAC to 0.500BAC; 0.100mg/L to 0.250mg/L.7. The "Danger" symbol is displayed with beep audible alert at: over or equal 0.050%BAC or 0.500BAC or 0.250mg/L.Notes:1. The first use of the tester or after a long time no use, press the power button, and retry several times if possible.2. Repeatedly 2 or 3 times to obtain more accurate results.3. Do not smoke and eat for 20 minutes prior to testing.4. The test result is for reference only.5. Powered by 2pcs AAA alkaline battery(not included), replace the battery when the LCD screen flashes for low power.6. Detection range: 0.000~0.199%BAC; 0.000~1.990BAC; 0.000~0.995mg/Lcolor: greymaterial: plastic[Working voltage]: 2 AA alkaline batteries (not included)Package Contents:1 x Digital Breath Alcohol Tester ( include 5 mouthpieces)Only the above package content, other products are not included.Note: Light and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.