MSA455021 / 455021 HOSE SUPPLY 25' NEOPRENE 3/8"ID MSA PremAire® Supplied-Air Respirator System The PremAire® System is an advanced modular respirator system that allows users to match specific respiratory protection needs by re-creating respirator configurations from one versatile unit. A lightweight, mask-mounted regulator provides high air flow and responds quickly to changing breathing requirements. The PremAire® Respirator consists of the patented PremAire® manifold with a variety of add-on options available. NIOSH approved.