The FAMCO GN Goose Neck Exhaust Roof Vent – Galvanized. Designed to use with bathroom or kitchen exhaust venting systems. This roof mounted vent comes with a damper to prevent back draft and with an insect screen. Quality constructed in 28 gauge Galvanized steel. The FAMCO GN Goose Neck Exhaust Roof Vent – Galvanized come in sizes: 4 inch, 5 inch, 6 inch, 8 inch, and 10 inch. This model is designed for hard pipe connections and does not come with an extension for flex tubing. Please see our GNX series for options with an extension for flex tube pipe. The FAMCO GN Goose Neck Exhaust Roof Vent – Galvanized is manufactured by FAMCO in the United States and comes with a 1-year warranty against product defects and workmanship. If you have any questions about this product, please refer to the FAQs above or feel free to contact us by phone or email. This vent is not intended for roof top dryer termination.