Pleatco filter cartridges are simply the finest replacement filters you can buy for your pool or spa. The Pleatco PA106-PAK4 Filter Cartridge is made of the finest filtration fabric. Its Free Flow Core creates rapid turbidity reduction that has superior dirt capturing and holding capacity. When using Pleatco filter cartridges the amount of time between cleaning and servicing is increased. Pleatco filters will reduce the water pressure and increase flow rate, while using less energy than other filter cartridges.