This cartridge is designed to use with the Pentair Quad D.E. filter model Quad 100. The straight, sharp and evenly spaced pleats create an efficient design for capturing and holding dirt. This filter features polyurethane end caps for strength and to create a proper seal in the filter. There are evenly spaced holes in the center core to distribute the water flow evenly through the cleaning cartridge. The Pentair Quad 100 D.E. replacement filter cartridge is a great choice for up to 25-square feet of water.