DuraFlex Pro is the ultimate in flexible steel liners for strength and flexibility. It features 20% more stainless steel per foot compared to other liners on the market. Its extreme flexibility facilitates problem free installations where multiple offsets are needed. DuraFlex Pro is available in 3" through 12" diameters in lengths, kits and custom lengths. DuraFlex Pro is manufactured utilizing highly corrosion resistant 316 Stainless Steel. Listed to UL 1777 and ULC S635.