Pleatco PMA40 2003 R Spa Pool Filter Cartridge brettaqualine The case of 12 format gives this The case of 12 format gives this product its value because it supports bulk purchasing convenience while maintaining the same application fit as the individual 2 pound units Recommended for qualified repair of pool and spa heating systems Filter cartridges are useful because they help maintain water clarity while supporting the overall performance of the filtration and circulation system This cartridge has practical value because a properly matched replacement helps restore filtration performance without the need to replace the larger housing or support components