Specification - F1100-N - Floor Drain with Tractor Grate for Non Membrane Floor Areas MIFAB series F1100-N7 - lacquered cast iron floor drain with anchor flange, weepholes, and 7" (175) satin finished nickel bronze tractor grate. (For membrane floors, use MIFAB F1100-C-N series). MIFAB series F1100-N9 - lacquered cast iron floor drain with anchor flange, weepholes, and 9" (225) satin finished nickel bronze tractor grate. (For membrane floors, use MIFAB F1100-C-N series).