Pentair 178654 Cartridge Replacement Quad 60 Pool and Spa D.E. Filter Cartridge replacement Straight, sharp and evenly spaced pleats for efficient dirt holding and capturing Durable polyurethane end caps for strength and proper sealing in filter tank Re-enforced center cores with a PVC center core for support Evenly spaced holes in center core for even distribution of water flow through the cleaning cartridge