Spun filter cartridges are made up of 100% polypropylene fibers. The fibers have been carefully spun together to form a true gradient density from outer to inner surface. Filter cartridges are available with core & without core version. The superior structure remains integral even under severe operating conditions and there is no media migration. Polypropylene fibers are blown continuously on central molded core, without any binders, resins or lubricants. Unfiltered fluid passes through depth filter matrix and enables the progressive retention of finer particles which provides high efficiency, high dirt retention & long filter life. Fluid flows from outside to inside through filter media. Particulates are held securely in the filter matrix and clean fluid flows to the downstream side of cartridge.