M G Duravent 6DT-CS36 Dura-Vent DuraTech 6 Inch square ceiling support box 36 Inch tall has been filling the supply and accessory needs of over 8, 000 sweeps hearth retailers masons and contractors for over 25 years. has the privilege of serving over 80% of the professionals in America.Founded by Robert Daniels Sooty Bob in 1978 has grown from a one-man operation to a national network of six warehouses and a manufacturing plant. From its headquarters in Fairfield Iowa plays a major role in providing for the industry. Ideal for flat or slightly sloped ceilings. Makes transition from DuraTech section to interior stovepipe at the ceiling. Includes 2in wide trim collar. (Requires choice of adaptor depending on style of interior pipe being used). 36 Tall. Dimesnions: 6 Square.