40inch pp string wound water filter cartridge with single core PP string wound water filter cartridges are manufactured from a ... filtration.Filter Media: Polypropylene with polypropylene core Cotton with with stainless core Glass Fiber with stainless core Filter Rate: 1um,5um,10um, ... 28mmCR-PPW40 is 40 inch pp string wound with a single core,and core thickness is 4.7mm,which ensure the cartridge can ...