The Big Daddy RD-800 series dual roof drain provides overflow protection. The drain eliminates the need to cut separate holes in the roof for overflow drainage. Available in 8- and 10-in. outlets, tests certified the 10-in. model achieved a 1,368 gpm flow rate. The RD-300-AC drain, available in sizes from 2 to 10 in., uses a compression-seal design. Features include a flashing clamp and gravel stop.