Certified Accurate For All Ages: Monitor asthma, COPD, and other chronic respiratory conditions at home; Suitable for both pediatric and adult patients; American Thoracic Society (ATS) standards for accuracy Early Detection for Asthma Attacks: Respiratory Risk Indicator (traffic light zones) alert to asthma attacks in advance, before you feel it; Contact your doctor in these instances Measure PEF & FEV1: Stores 240 readings; Peak Expiratory Flow Rate (PEF) measures how well you are breathing; Forced Expiratory Volume in one second (FEV1) measures how well the lungs are working Stay Clean & Organized: Removable mouthpiece and measuring tube are easy to clean; Kit includes x3 mouthpieces; Premium two-tier storage case keeps everything separated and ready for use Free Monitoring Software: Connect to computer via USB to upload results to the Microlife Asthma Analyzer; View and track results, customize traffic light zones, and share results with your doctor; Windows and Mac compatible