Collar W/Damper, Duct Fitting Diameter 8 in, Duct Fitting Length 5 in, Width 10 in, Duct Fitting Material Galvanized Steel, 24 ga Gauge, Collar W/Damper, Height 6 in, Coating Galvanized, 3 in W.G, Standards SMACNA / ASTM, Pre-sealed / Low Leakage Hardware, For Use With Greenseam Duct system Package of 5.