9" x 9", Stainless Steel Shelter Chimney Cap, 100% 304 Stainless Steel, 24 Gauge Single Piece Stainless Steel Hood, 18 Gauge 3/4" Expanded Stainless Steel Mesh, 16 Gauge Stainless Steel Base For Extra Strength, Will Prevent Certain Kinds Of Downdraft, Keep Birds, Squirrels & Animals, Keep Out Leaves, Limbs & Debris, Arrest Sparks & Help Prevent Fires, & Protect Flue From Moisture.