Gelco 13401 8"x8" Single-Flue Chimney Cap. This Chimney Cap is an excellent choice in protecting your homes chimney from moisture and objects. This Gelco 13401 8"x8" Single-Flue Chimney Cap. This Chimney Cap is backed by a 3 year warranty. The Cap also features a metal mesh surrounding capped off with a 8"x8" square cap.