The Highest Water Clarity with the Lowest Amount of Fuss. Quad D.E.? Filters combine the finest filtration available for the most sparkling clear water with the convenience and easy-cleaning features usually found only in a cartridge filter. Four easily accessible and removable D.E. cartridges simplify maintenance and save time.An Eco Select Brand Product: Water flows very efficiently through Quad D.E.? 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.