The FAMCO Globe Vent GBV is an economical, gravity ventilator for use on residential, commercial and industrial applications. The GBV features water tight construction and a low silhouette while offering positive draft for good air flow. The draw bolt collar (available in sizes up to 12”) offers secure fit yet is easily removed when needed. This product is constructed in 28-24 gauge Galvanized Steel. Note: This product uses the FB, PB and SB - Round Vent Bases on certain applications.