The unique structure design of RK12 Series filter cartridge makes no extra treatment costs of replacement and housing cleaning, no physical touch of feed liquids, fit for the filtration of poisonous and harmful slurry. Capsule structure reduces the gap between the filter housing and the inner core,which means, decreased slurry residues. The inner core could be selected upon request, length 5''/10''/20'' are optional. The new drainable patented-design structure performs the perfect recycing of slurry. It's suitable for RK12 filter housing.