Specification - F1100-C-FT - Floor Drain with Recessed Flange for Membrane Floor Areas MIFAB series F1100-C-FT6-1 lacquered cast iron floor drain with anchor flange, cast iron membrane clamp ring with primary and secondary weepholes for waterproofing membrane, and standard reinforced 6" (150) diameter satin finished nickel bronze strainer with 1/8" (3) recessed tile flange. (For non membrane floors, use MIFAB F1100-FT6 series).