18ga. (.048) Heavy Duty Trash Grommet will fit into 12” hole. Flange outside diameter is 12 7/8”. Countertop stainless steel grommet, Stainless Steel Trash Ring 15” 12” 10” 9” 8” 7” 6” 5” 4” 3” 2” Diameters. Custom rectangular, square & round grommets are available.