... °C (5) Port Size: Mini-1/8", 1/4", 3/8"; Midi-1/4", 3/8", 1/2", 3/4"(6) Min. Standard Normal Flow Rate ... -3/8-Midi, OF-1/2-Midi, OF-3/4-MidiSelection CriteriaOrdering exampleModel: OF-1/4--Midi0F-Midi-Air Filter, Port Size 1/4" OF-3/8 ... -Midi Festo Air Filter