The Zodiac R0357900 Filter Cartridge is a high-performance filtration solution intended for pool and spa systems that require effective debris removal. This filter cartridge has a large filter area of 145 square feet, making it an excellent choice for applications that require complete filtering. To achieve peak performance, four of these cartridges are required to cover a total filte... https://www.usapoolshop.com/r0357900-zodiac-145-sq-ft-filter-cartridge