The Forever Cap CCSS1321 Inch Stainless Steel 5/8-Inch Spark Arrestor Mesh 13 x 21 Forever Chimney Cap, Eight Will fit masonry clay flue sizes from 11 inch x 20.5 inch to 14 inch x 22 inch Hood size is 20 inch x 20 inch 24 Gauge Made in the USA Lifetime Warranty