It is widely known that a pump directly sucking oil from the vehicle oil tank, without a correct filtering device, can come in touch with impurities able to cause damage to the pump, the distributor and the valve. In order to protect the life of the pump and the hydraulic system, it is necessary to introduce the proper filter against the smallest oil impurities. We have released a small size filter series which can easily be installed in the hydraulic circuit according the technical specifications of the filter type. This “PATENTED” filter series, thanks to the peculiar axial shape and to the high efficiency, allows the filtering of big oil flow with very limited pressure drops.