Our 304 stainless steel chimney chase covers are a piece of steel custom-made to seal off the top of the chimney in order to prevent moisture from seeping in. Chimney chase covers are shaped like the lid of a shoebox and are commonly installed with pre-fabricated fireplaces that have a wood-frame chimney chase. Some masonry chimneys can also use this style of chimney chase cover, which can also be called a “chase pan”. A cap is attached to the chase cover in the case of prefab chimneys and is attached directly to the brick of masonry chimneys. A chase cover is a metal cover that fits over your chimney chase (on chimneys with wood, metal, or vinyl siding) to prevent water from entering the chimney