Cobetter Mini Filter Cartridges 56 series diameter are 56mm, provide absolute, accurate filtration for most critical needs in a wide rage of process liquids and gas. The 56 series-filter design allows minimal hold-up volume and particle shedding, meeting exacting specifications for chemical compatibility, flow rates, thermal tolerances, high dirt-holding capacity and long on-stream life. The 56 series-filter consists of a broad range of controlled porosity graded density depth media housed in chemically stable polypropylene.