20 BIG PS GD 05 - 20" X 4 ¼" Big Gradient Density 5 Micron Polyspun
30 to 5 Micron Density. Suitable for all 20" Big Blue and Jumbo sized housings. Holds more dirt and impurities than normal Depth poly spun or pleated filters. Please note this filter is not a normal Polyspun Depth Cartridge it is the highest quality NSF approved Dual Gradient Density.