- Portable breathalyser with police-grade accuracy. Uses advanced semiconductor sensors to deliver accurate readings quickly. Measurement range: 0.00-0.19% BAC (0.0-1.9 g/L). Fast response and fast recovery. - High-precision sensor and airway design. Professional promille meter with semiconductor sensor technology provides accurate results and sounds an alarm if the reading is too high. - Easy to use. Requires 2 AAA batteries (not included). After warm-up, a blow indicator appears. Blow into the mouthpiece for 2-3 seconds and wait 10-15 seconds for the result. Auto-off to save power when not in use. - 5 interchangeable mouthpieces. Comes with five mouthpieces and an LCD display, so you don’t have to worry about forgetting a mouthpiece when on the go. - Use scenarios. Check sobriety before driving at home or with friends; perform workplace safety checks; use at events or while traveling to verify levels quickly.