Piloted Check Valve Hgl-1/8-QS-6 with Sealing Ring Ol, with Qs Push-In Fitting. Valve Function=Piloted Non-Return Function, Pneumatic Connection, Port 1=Qs-6, Pneumatic Connection, Port 2=G1/8, Type of Actuation=Pneumatic, Pilot Air Port 21=M5, Festo