The air flow rate indicator provides a convenient way to determine SCFM of air flowing through a duct or hose. The units are equipped with flex duct collars for diameters 6", 8", 10" and 12" on both ends. Flow rate is directly read on an integrally mounted Magnehelic Gage. An additional collar for modifications can allow direct mounting of the unit to the inlet collars of RPS HEPA filtration units. Custom collars and transitions can be provided per request. The inline airflow rate indicator displays flow accuracy within 2.5% of display range. Control options are listed below.