MIFAB® R1150-SPEC Series combined roof drain and secondary overflow system, consisting of a galvanized sump receiver; two lacquered cast iron roof drain bodies with anchor flanges, cast iron waterproofing membrane clamp rings with integral gravel stops, one 4" (102) diameter adjustable ABS overflow standpipe and two self-locking metal dome strainers with a free area of 43 square inches each.