Side valve blanking Plug.
Save money and convert your side manifold valves into stand alone cylinder valves, with the use of a blanking plug.
The blanking plug has double o-ring protection. Simply unscrew your manifold bar and screw in the blanking plug.
The right hand blanking plug has a right hand thread and the left hand blanking plug has the reverse thread.
You can distinguish between the left and the right hand blanking ports by looking at the notches cut in the nut head of the left hand plugs.