The Paramount Retro Cover comes with screws, ready to install into a new pool or a reconstruction of a current pool. Comes in 6 different colors for all of your pool color needs. The Retro cover for concrete pools eliminates the need to chisel out a sump below the drain. One drain in the floor of the pool drains 188 GPM and if the drain is on the wall, you can expect a drainage of 154 GPM. The SDX2 Retro fits existing drain covers in a concrete up to a 10" diameter drain cover. SDX2 is approved as a bulkhead fitting so there is no need for the pipe to be 1 1/2 times the pipe diameter from the cover. The SDX2 provides uniform suction regardless of the pipe location.