Hayward cartridges are designed to meet nsf's high quality performance & durability standards with Hayward filters. Only Hayward replacement filter cartridges will provide maximum hydraulic efficiency, exceptional first pass debris removal & extended durability with Hayward cartridge filters.                                                       
  
 Nsf certification requires the use of genuine Hayward replacement cartridges  
  
 Precision engineered, molded and extruded cores provide maximum hydraulic efficiency and overall structural stability  
  
 Specifically designed for maximum performance of Hayward cartridge filters