From the PelletVent Pro collection, designed for biofuel chimney system, brings to you the DuraVent 4PVP-FTC flex trim collar. This is to be used to connect PelletVent Pro rigid pipe to your masonry chimney. It also has a stainless steel flexible relining with a female end swivels to easily connect it. Made of super ferritic stainless steel that makes it very resistant to corrosion, this measures 4 inches of inner diameter and is considered as a UL-listed product.For your venting and chimney system, trust only DuraVent as it has proven itself a technological leader in creating innovative and high-quality products. Get their products only here at PlumbersStock.com.