This cap has been designed to be used with the PCO38 Tapping Head for the PET Mini Keg Range. 

As it is a standard PET bottle thread (PCO1881). it can also be used on the FermZilla Collection Container / Lid.

Use with any of the four PRV valves (sold separately) - 17, 35, 65, 100PSI.

Please Note: Never exceed the pressure capabilities of your vessel. PRV's are not spunding valves!