SmoothWall Double Ply Stainless Steel Chimney Liner Kit – 4″ x 40′ SmoothWall Double Ply Stainless Steel Chimney Liner Kit – 4″ x 40′. Includes: Section of our smoothwall double ply liner, Tee & tee cap, Top plate with collar, Round Cap and fasteners, Installation instructions and homeowner’s warranty Card. Features: Made in USA. Everything you need in one kit to do the job. Tested by Conran Inspection Inc. Tested and approved to UL1777 Zero Clearance Standards. All of our kits are backed by a Lifetime Warranty. Specifications: Overall Dimensions: 40′ (L) x 4″ (W) x 4″ (D) .