Reinforced thermoplastic filter tanks made from extra durable glass reinforced copolymer material to meet the demands of toughest applications * Extra-large cartridge element with new precision engineered extruded core provides extra-strength and maximum flow * Single locking knob securely fastens head to filter tank, eliminating bolts or clamps * Attractive, durable filter head, rotated to conveniently position pressure gauge and manual air relief; 120-Square-foot 2-inch FIP pipe pool filter * Extra-large cartridge element with new precision engineered extruded core provides extra strength and maximum flow