Flex hoses are used to connect the agent storage containers to the manifold in multiple cylinder arrangements. Flex hoses are constructed of high pressure hydraulic rubber in the 1" and 1-1/2" sizes and stainless steel corrugated inner core with stainless steel braid in the 2-1/2" size. All sizes are fitted with male NPT thread on both ends. There are two options available for the1200 LB Cylinder. There is a flex hose and a flex and check valve assembly. The flex hose alone is 4" diameter (Part # LF91230) and is 30-1/2" in length; it is constructed of a stainless steel corrugated inner core with stainless steel braid. The flex hose has 4" Victaulic fittings on both ends. The combination flex hose and check valve is used when using a manifold in a piping network. The combination flex and check valve assembly is 4" diameter (Part No: LF91231) and is 26-1/2" in length, it is constructed of a stainless steel corrugated inner core with stainless steel braid. The flex hose is fitted with 4" Victaulic fittings on both ends.