Bolt On Single Flue Stainless Steel Chimney Cap with Big Designer Lid Call for Quote Products The rigid liner support clamp The rigid liner support clamp is also helpful when installing the rigid chimney liner protecting your clay flue by installing our copper single flue cap is simple Size Lid Size Fits Flue Size 9 x 9 18" x 18" 8" x 8" to 9 1 2" x 9 1 2" 9 x 13 18" x 22" 8" x 12" to 9 1 2" x 13 1 2" 9 x 18 18" x 27" 8" x 17" to 9 1 2" x 18 1 2" 12 x 12 21" x 21" 11" x 11" to 12 1 2" x 12 1 2" 13 x 13 22" x 22" 12" x 12" to 13 1 2" x 13 1 2" 13 x 18 22" x 27" 12" x 17" to 13 1 2" x 18 1 2" 18 x 18 27" x 27" 17" x 17" to 18 1 2" x 18 1 2" Measuring for Your Chimney Cap with Big Pitched Lid measure the length