Clean & Clear? Plus Filters have a corrosion resistant injection molded filter tank featuring superior strength and reliability. The cartridge assembly uses four easy to clean, non-woven, polyester cartridges. Each filter is supplied with a bulkhead union set for easy installation.An Eco Select Brand: Water flows very efficiently through Clean & Clear? Plus Filters filters allowing the use of smaller pumps or lower pump speeds to minimize energy use. And when consumers rinse cartridges rather than backwash, they can significantly reduce water use, too.