Quick connector ACK-1/4-PK-6 Female thread with sealing ring. Nominal size=5,3 mm, Type of seal on screw-in stud=Sealing ring, Assembly position=Any, Operating medium=(* Compressed air in accordance with ISO8573-1:2010 [7:-:-], * Water as per manufacturer's declaration at www.festo.com), Note on operating and pilot medium=Lubricated operation possible