The Shasta Vent universal chimney cap fits most all-fuel chimneys that have a 8″ inside diameter. This cap secures to the chimney by fastening the down-straps to the wall of your existing chimney with sheet metal screws thru the outer wall of your existing chimney. This cap is designed for maximum ventilation. It is a rain cap and comes with a spark arrestor screen. The cap is made of 304ss which is a superior grade of ss for all climates, including coastal conditions with salt spray.