For safe and efficient venting while protecting the masonry chimney, the DuraVent 6DLR-60OF is an oval-to-oval flex pipe from the DuraLiner collection. This is designed to be used through damper and smoke shelf area with the DuraLiner Insulation Kit. Made of stainless steel construction, it has a diameter size of 6 inches and a length of 60 inches. It is a UL-listed product and is covered by DuraVents limited lifetime warranty.Innovation and style has been the trademark of DuraVent throughout the years in the venting industry. Get one of their products here at PlumbersStock.com.