The DuraVent 6DF316-25K DuraFlex 316 basic kit is a flexible relining for your masonry chimney. Designed to be used in harsher conditions, it is corrosion-resistant and can be used with gas, oil, wood pellet or wood appliance. This has an inner diameter of 6 inches and a length of 25 feet. The kit also includes a DuraFlex SS top plate, DuraFlex SS cap, DuraFlex SS connector, and DuraFlex 316 length.Search only for the best and high-quality products for your vent system. In cooperation with DuraVent, PlumbersStock.com has everything you need at affordable prices. Go find yours now here at PlumbersStock.com!