Rockford Chimney Supply Chimney Liner Insulation Blanket Kit, 3 to 6 Inch Diameter x 15 Feet RockFlex Chimney Liner Insulation Kit Includes everything to complete the job RockFlex Chimney Liner Insulation has the best thermal insulating performance on today's market UL1777 Listed in the USA; The very best chimney zero to zero clearance listing Installation support before and after the sale; we're here to help you do it yourself Will fit stainless steel flexible chimney liner diameters 3, 4, 5, 5.5, 6, 6.5 inch