This Is The Bottom Elbow Assembly For A Hayward S-310S Sand Filter. This Is The New Version Used On Filters Made 1996 And Later S310-EB2 Is Molded Into The Elbow Part The Face Of The Assembly Where The Bulkhead Fitting Screws In. It is Flat And Has Triangular Shaped Ridges Built Into The Face. Length: 15" (From Back Of Elbow To Front Where Fitting Screws In) Height: 7-1/2" (Total)