Steel adapters connect RS fans to factory-built chimneys. Stock sizes are listed to the right. Over 50 sizes, from 5" to 24", are available directly from the factory for solid packs and air-cooled chimneys. Call if your specifications require a non-stock adapter. An adapter plate is also needed if the fan is not as large as the Chimney opening. Again, call for this out of stock item. Includes: 3' fan cable, junction box, and adjustable rheostat speed control. Features: Solve the worst eraser problems by creating your own eraser. Without maintenance. 6-month money back guarantee. 10-year warranty against corrosion, 2-year warranty against defects in materials and workmanship. For use with RS12 or RS14 fan. Specifications: Overall Dimensions: 8'' (W).