15x15 Ductile cast iron grate, C ClassThis cast iron grate works perfectly with Vodaland 16x16 Base plastic catch basins and is C class load rated. Check drawing to make sure that dimensions work for your project. The 15x15 base ductile cast iron grate is 15 inches square, and its lowest point extends 2 inches deep (see drawing: dimensions below are rounded up) to fit our mid sized 16x16 catch basin. The openings are 1 inch square. This sturdy, heavy duty cast iron grate keeps larger