12 Interchangeable Mouthpieces Breathalyzer comes with 12 pieces of mouthpieces, which can be cleaned and reused. Super compact design fits in your pocket and is easy to hold and carry. Ideal for personal use. The breathalyzer features a professional airway design and high-precision semiconductor sensor to deliver fast and accurate blood alcohol concentration (BAC) readings. Test results range from 0.00% to 1.9% BAC or 0.0 to 1.9 g/L. Alarm function activates when BAC exceeds 0.05% or 0.50 g/L, emitting a continuous beep to alert the user. Backlight display ensures easy reading in low light. Easy to use: insert 2 AAA batteries (not included), turn on the device, wait 20 seconds for warm-up, then begin testing. Auto power-off function conserves battery life. Package includes: 1 x Breathalyzer, 12 x Mouthpieces, 1 x User Manual.