National Stainless Steel Premier Top Hinge MF Cap-17"X29"- 12" Easily attaches to the top of the chimney Made with a 24 gauge removable 100% 304 Stainless Steel hood Acts as a spark arrestor to prevent most ascending sparks from reaching the outside Recommended for use in situations where Oil or Coal is burned, or when Wood/Pellets are used as primary source of heat