Specification - F1100-C-EF - Round Funnel Floor Drain for Membrane Floor Areas MIFAB series F1100-C-EF-1 lacquered cast iron floor drain with anchor flange, cast iron membrane clamp ring with primary and secondary weepholes for waterproofing membrane, and standard 4" (100) round satin finished nickel bronze funnel assembly. (For non membrane floors, use MIFAB F1100-EF series).