Spare 2" Cap Complete with Stainless Steel valves

This fits most barrels with a 2" neck.  Anything under 10 years old it will fit

 

Your valve may be brass but these are better!

If it's too small to get your hand in then it's this cap.

There are some old barrels which it doesn't fit!

You can have it with a pin valve for the 8gm Co 2 Bulb  or for S30 Refillable cylinder--