12 Interchangeable Mouthpieces Breathalyzer includes 12 reusable and washable mouthpieces. Compact and portable design fits easily in your pocket, making it convenient to carry anywhere. Ideal for personal use by drivers. Features a professional airway design with a high-precision semiconductor sensor for fast and accurate blood alcohol concentration (BAC) testing. Measures BAC levels from 0.00% to 1.9% (0.0 to 1.9g/L) with reliable performance. Alarm function activates with a continuous beep when BAC exceeds 0.05% (0.25mg/L), alerting users when levels are above legal driving limits. Backlit display ensures easy reading in low-light conditions. Simple to operate: insert two AAA batteries (not included), power on, allow 20 seconds for warm-up, then begin testing. Automatically powers off after inactivity to conserve battery life. Package includes: 1 Breathalyzer device, 12 Mouthpieces, and User Manual.