Mastercool 48364 Black 36" Nylon Barrier 1/4" I.D. Hose 3/8" Flare Fittings - With a working pressure of 800 PSI and a burst pressure of 4,000 PSI and 3/8" fittings. Mastercool uses only (GRADE 5 HOSE) with a selection of Standard and Nylon Barrier for high pressure applications. Knurled brass nuts make finger tightening easy. Crimped with 8 segment dies for secure fit and maximum durability. Hoses are available in sets and a variety of lengths to meet all EPA, SAE, and UL requirements for containment of refrigerant. Auto shut-off valves automatically retain refrigerant in the service hose when they are removed from the system, meet EPA, SAE, and UL standards for containment of refrigerant.