Return filters are used as process and safety filters to protect pumps and hydraulic circuits from contamination as per ISO 4406. They are available in 4 styles : * SMP semi-immersed filters for mounting to the oil tank with external/internal filter element * MPT semi-immersed filters for mounting to the oil tank with external/internal filter element * MHP/MPI semi-immersed filters for mounting to the oil tank with external/internal filter element * FRI semi-immersed filters for mounting to the oil tank or in-line, available in the single or duplex versions, with external/internal filter element