Clean & Clear Plus Cartridge Pool Filters have a corrosion-resistant, injection-molded, fiberglass-reinforced, polypropylene filter tank featuring superior strength and reliability. The cartridge assembly uses four, nonwoven, polyester cartridges. There is no need for backwashing.

• Large filter area for increased dirt capacity
• 100% drain clean-out port
• Continuous High Flow™ Internal Air Relief*
• Durable injection-molded tank
• Balanced hydraulic flow
• Available only in store from Pentair dealers or retail stores

For more information: 

https://www.pentair.com/en-us/products/residential/pool-spa-equipment/pool-filtration/clean_and_clear_pluscartridgefilters.html