Chimney has been filling the supply and accessory needs of over 8,000 chimney sweeps hearth retailers masons and contractors for over 25 years, Chimney has the privilege of serving over 80% of the chimney professionals in America, Founded by Robert Daniels ""Sooty Bob "" in 1978 Chimney has grown from a one-man operation to a national network of six warehouses and a manufacturing plant, From its headquarters in Fairfield Iowa Chimney plays a major role in providing for the Chimney industry, Whenever you are passing a direct vent through combustible materials you must use a firestop, So why not use a Direct Vent Firestop Spacer? Compatible with all Direct-Temp piping, this venting accessory features a durable construction and can be installed in just minutes, Selkirk"s Direct-Temp line of venting products stands out amongst its competitors because of its unique blend of versatility and strength, For example, how many other brands of piping are capable of venting corn, pellet, and gas heating appliances? And how many boast a construction resilient enough to resist corrosion and leaks, yet still appear elegant? This series also includes a variety of specialized items, like this Direct Vent Firestop Spacer, to help you find a solution for every type of venting challenge, There"s no better choice than Direct-Temp for convenient and reliable venting, Wall firestop for horizontal through-wall installations, For use with Direct-Temp venting products, Lifetime warranty, 6-5/8"" Opening, Dimensions: 12"" W x 17"" L, SKU: CPPF5756