Mobile, portable filter units with integrated motor/pump units as cost-effective alternative to permanently installed partial-flow filters. Allows professional filling, flushing and cleaning of hydraulic systems and lubricating oil systems. Compact, lightweight and therefore extremely flexible. Viscosity-dependent nominal flow rate up to 15 l/min. Use with spin-on filter elements with a filter grade between 3 and 125 µm. On request also with empty element for pumping used oil out of a container.