CFM tester checks the volume of air that gets to the respirator. A flow meter simply quick connects onto an airline hose to check the respirator system for NIOSH compliant air flows. The kit contains flow meter and a full assortment of quick connect plugs and adapters to fit all respirator manufacturer’s airline hoses. Excellent for use with ambient air pumps. NOTE: NIOSH mandates 4 CFM for tight-fitting masks and 6 CFM for hoods.