CCP420 replacement cartridges. Four (4) Pack of Filter Cartridge Elements for the Clean & Clear PLUS 420; 105 SQ.FT. pool filter. C-7471 replacement cartridges. Manufactured by Optimum Pool Technologies with the highest quality materials for easy cleaning and long life. Replaces OEM# 178584 , (R) 173576, Unicel# C-7471 / C7471 , Pleatco# PCC-105 / PCC105 , Filbur# FC-1977 / FC1977