Inner Cartridge: 8-3/4″ 25-1/4″. Outer Cartridge: 16-1/2″ 18-3/4″. Max flow:100 GPM, Max PSI: 50. Durable 4oz Reemay filtration fabric. Chemical resistant feinforced end caps. ABS injection molded full flow cores. Pleat bands ensure pleat stability. ZOTEE Filter Cartridges are designed with Unique trilobal fiber structure and Highly-uniform media which delivers better filtration perpormance and offer a longer life than most replacement filter cartridges. High Dirt Holding Capacity – Less frequent cleaning. Durability – Withstands the rigors of multiple cleaning. Filtration Efficiency – Dependable filtration for clean water. ZOTEE Filtration Pool Filters System-3 is designed as direct replacements for the manufacturers original cartridges. No adapter plate is needed, just remove the old filter and replace it with a new one!