Hayward C9002S Star-Clear Plus 90-Square-Foot Cartridge Filter, 2-Inch SKT Pipe Filter tanks made from extra durable glass reinforced co-polymer material to meet demands of the toughest applications and environ mental conditions Single piece injection-molded base and body provides added strength for reliable, corrosion-free performance Single locking knob securely fastens head to filter tank, eliminating bolts or clamps; 90 square foot cartridge filter Attractive, durable filter head may be rotated to conveniently position pressure gauge and manual air relief Measures 2 inches socket pipe, extra-large cartridge element with new precision engineered extruded core provides extra-strength and maximum flow