Typically used on beer outlet/gas inlet of keg couplers. Cone supports ‘Top Hat’ type Duck Bill Valve.
How to make a connection
Cut the tube square.

Push up to tube stop
Pull to check secure
Pull on the tube to check it is secure. Test the system before use.
pieces available
Female adaptor small cone end OD tube 1⁄2″ × BSP thread 3⁄4″ NCPI451214CS