This 4-cartridge pool filter set replaces the multi-cartridge bank in a Pentair CCP420, Pleatco PCC80-PAK4, Unicel C-7471, or compatible housing in one shipment—so a pool service completes a full-service swap in one weekend instead of waiting four separate deliveries. Each cartridge delivers 105 sq. ft. filter area for 420 sq. ft. total. The 26 in / 661 mm core length and 7.01 in / 178 mm outer diameter match the per-cartridge area of 420-series filters and the higher flow rate they handle. Trilobal pleated fiber (181 folds, 100 g/sq.m fabric) delivers exceptional dirt-holding capacity—pleat geometry traps debris that single-layer weaves release during backwash. EPA-certified 50-micron filtration captures hair, leaves, fine dust, and fine particles that slip through 75-micron budget filters. Keeps chlorinated water crystal-clear. PA+GF reinforced end caps prevent collapse under backpressure—longer intervals between replacements. Fits GL-420-1, Pentair CCP420, Pleatco PCC80-PAK4, 178584, Ultraf-A6, Unicel C-7471, 817-0106, R173576, Filbur FC-1977, 570-0425-07. Third-party compatible accessory; brand names for reference only. Core 661 mm / 26 in; OD 178 mm / 7.01 in; ID 76 mm / 3 in; inlet/outlet 3 in / 7.6 cm; fold 181; 4 per box (420 sq. ft. total); net 4.19 lbs / 1.9 kg. Model GL-420-1.