This is the 45 sq ft cartridge outside cartridge used in the Master Spa Eco-Pure filtration system. This is the microban anti-bacterial version.
The X268340 fits inside of this cartridge.
PMA45-2004-R is molded on the top.
Replacement Spa Filter Cartridge
Part # PMA45-2004R-M
The 10 sq ft cartridge fits inside the 45 sq ft.
See below for related cartridges or for a set.