These No. 4 Braided Flex-Hose, (4jic-Female Brass swivels on Both ends) braided (PTFE) Teflon flex-hoses are cleaned for oxygen system applications. They are rated for 3000 source (12,000 burst) psi service and are ideal for applications that require a remote fill-port. Hose assemblies are cleaned for oxygen service per specification (SAE) AIR1176-A. 2 to 20 foot lengths available and stocked. Special orders accepted for custom length applications. Expect 2 weeks for custom orders.