Fuel Cell Breathalyser with Advanced Flow DetectionThis personal breathalyser uses an internal fuel cell to measure alcohol in your breath, which is one of the more accurate ways to test. Testing is simple, and blood alcohol is presented as a percentage on the backlit LCD display. Of course, all measurements are an indication only and you should only use them as a guide. The safest blood alcohol to drive with is zero. Features include a breath sample flow check, memory of the last 16 results,