High precision digital breath analyzer: This alcohol tester features a high-precision semiconductor alcohol sensor that quickly delivers accurate results to help determine fitness to drive. Measures BAC from 0.00% to 1.9% and displays results on an easy-to-read LCD screen. Ideal for personal use by drivers. Easy to use: Simply insert two AAA batteries (not included), power on the device, allow 10 seconds for warm-up, then breathe into the mouthpiece for 3 to 6 seconds. Results appear instantly on the display and remain visible for 10 seconds before the unit automatically powers off. Auto alarm function: If the BAC level exceeds 0.05%, the device emits a continuous audible alert to warn the user against operating a vehicle. For best accuracy, wait at least 20 minutes after consuming alcohol before testing. Lightweight and portable design: Compact size allows for convenient storage in a pocket or bag. Suitable for use at social events such as parties, weddings, and celebrations to support responsible decision-making regarding driving.