Hayward DE4820 ProGrid D.E. Pool Filter, 48 Square Foot, Vertical Grid Vertical grid filter for in-ground pools and spas of all types and sizes Inlet diffuser elbow distributes flow of unfiltered water evenly to all filter elements and provides even distribution of D.E. to grids Plumbing options allow for customized control; heavy-duty, tamper-proof, 1-piece flange clamp securely fastens tank top and bottom. Allows quick access to all internal components without disturbing piping or connections, valve not included 2-inch full-flow internal piping and plumbing for less resistance to flow and maximum performance 48 -foot filter allows for both commercial and large residential applications and years of non- corrosive, trouble-free performance