feature:   1. High sensor, accurate test: The breath alcohol tester also provides you with reliable and stable results every time you test, with an error of less than 1.76%, suitable for personal, professional, third-party organizations, drivers, parties, family gatherings, subject to Hospital trusts, clinics and even law enforcement   2. The Most Accurate Respirator Available: As you strive to drive more responsibly, you need the most accurate results. While some breathalyzers give inconsistent readings and make you wonder what your true BAC reading is, ZBK breathalyzers will always give you police-grade accuracy for your safe driving   3. Practical and easy to use: Blow for 3-5 seconds and your BAC result will be displayed on the bright, easy-to-read LCD screen after 10 seconds. Alcohol Tester Breathalyzer Lithium battery powered with 5 reusable mouthpieces. Wait 13 minutes after drinking for the most accurate results   4. Portable Alcohol Testers: Professional alcohol testers, from roadside law enforcement officers to hospital and treatment professionals. 5-second response time for easy portability; measures only 5.3x 1.875 x 0.625 inches and fits easily in your pocket.   5.4 replaceable cigarette holders: This alcohol tester comes with 4 replaceable cigarette holders, so you don't have to worry about the embarrassment of friends or the opposite sex using one.     specification:   Model: Portable High Precision Alcohol Tester   Power supply mode: built-in 3.7v 200MAH lithium battery, USB power supply   Product size: 13.5cm*4.1cm*3.5cm   Material: ABS     Package Included:   1 host   1 copy of the manual   1 USB cable    4 mouthpieces