Specification - R1100-PR - Promenade Deck Drain MIFAB series R1100-PR lacquered cast iron roof drain with anchor flange, cast iron waterproofing membrane clamp ring, and standard 1" (25) thick, 8" (203) square adjustable ductile iron tractor grate with 3/8in (9) maximum width drainage slots and a free area of 20 square inches.