The AlkoStar ACE Y-Series is a self-calibrating "one-button breathalyzer" that measures the alcohol concentration (approximately +/- 5% at 1.00 per thousand) based on the breath. The electrochemical sensor used is a new development of ACE GmbH from Germany, and more accurate than the semiconductor sensors often used. The device displays the alcohol content of your breath both in parts per thousand and in grams per liter. The AlkoStar ACE Y-Series takes a measurement after an automatic calibration (about 15 seconds) and displays within 5 seconds, the measurement results on the display.