Our 3/4″ diameter Low Pressure Airline Hoses are specifically designed for our Breathing Air Blower and Cold Air Systems are NIOSH approved when used with the approved Allegro Supplied Air Respirators. They’re constructed from rugged clear polyvinyl chloride, reinforced with braided polyester textile yarn, and are manufactured with Parker quick-connect couplers. These hoses offer an operating temperature range from 25° F to 150° F (-3.8° C to 65.5° C).