Speedi-Products EX-RCG 48 4-Inch to 8-Inch Diameter Plastic Gooseneck Roof Cap, Black Speedi-Exhaust Products are made in the USA Collar adapts to 4-Inch and 8-Inch pipe Removeable Screen and Backdraft Damper UV Protected Polymer Resin Seal joints with approved duct mastic sealants and tapes