Alliance Analytical, Inc (AAI) 578 Eccles Ave , South Sanfrancisco , CA 94080 USA About Solutions products services software Home breadcrumb Companies Alliance Analytical, Inc (AAI) Products Airflow Indicator - Model 520-01-21 - 3M Flow Meter Airflow Indicator - Model 520-01-21 - 3M Flow Meter From AAI - Air Flow Meter 0 Share Share with Facebook Share with Tweeter Share with LinkedIn The 520-01-21 and AFI-100 flow meters are designed to: Check airflow being supplied by the3M Breathe Easy unit. The 520-01-21 may be used for all: 3M Breathe Easy systems including those using theRBE-BTB tube. Most popular related searches flow meter flow metering air flow meter Customer reviews No reviews were found for Airflow Indicator - Model 520-01-21 - 3M Flow Meter. Be the first to review! Add your review Publish your review Great! review successfully added!