MIFAB® Series R1230 combined medium sump roof drain and secondary overflow system; consisting of 20” x 40″ galvanized sump receiver, two lacquered cast iron roof drain bodies with 12” diameter anchor flange, cast iron waterproofing membrane clamp rings with integral gravel stop, one 2” high water dam and two self-locking cast iron dome strainers with a combined free area of 160 square inches.