Portable breathalyzer is designed to help you drive safely after drinking in a business negotiation, family gathering, party, dating or more situations. It adopts advanced flat surfaced alcohol sensor which brings quick and accurate results. Better repeat testing for 2-3 times and DO NOT drive if you are drunk. Features: LCD digital screen with blue backlight, clear at a glance. The alarm value is 0.05% BAC (0.5g/L), with audio and visual dual alarm. Adopts advanced flat surfaced alcohol sensor, easy operation, quick and accurate result. Better repeat testing for 2-3 times. Equipped with 6 mouthpieces in total, easy to install or remove, satisfying the whole family needs, more sanitary. Powered by 3 AAA batteries (not included) or DC 5V external power, choosing according to practical conditions. Compact and lightweight, portable to carry in pocket, backpack, laptop bag, car and so on. Note: Size and color may be slightly different due to manual measurement and different light conditions. Thanks for understanding. Specifications: Color: Black & Silver Material: ABS Display: LCD Backlight Detection Range: 0.00-0.20% BAC, 0.00-2.00g/L Alarm Value: 0.05% BAC, 0.50g/L Accuracy: ±10% F.S Power Supply: 3 * 1.5V AAA Battery (not included) or DC 5V External Power Working Environment: -10~50, ≤95% RH Item Size: 105 * 80 * 25mm / 4.13 * 3.15 * 0.98in Item Weight: 65g / 2.29oz Package Size: 16 * 10 * 5cm / 6.30 * 3.94 * 1.97in Package Weight: 112g / 3.94oz Package List: 1 * Breathalyzer 6 * Mouthpiece (1 mouthpiece already installed) 1 * User Manual (English)