Parker Stainless Steel Pipe Fitting, Straight Hexagon Plug

The Parker plug seals a port on a tube fitting, featuring a pre-installed machined ferrule. The cap closes off instrumentation tubing, comprising a complete assembly with a nut, front ferrule, back ferrule (for two ferrule A-LOK fitting only), and a blank

NACE and NORSOK standard
It has applications in instrumentation hook-up systems and analytical installations