The Patented Furick Moose Knuckle #14 has an inside diameter of .875 inches/ 22mm and is recommended for DC polarity applications only, it uses anywhere from 25-30 + CFH of Argon flow. It is recommended for 3/32 / 2.4mm tungsten size and carries a 180 amp rating on constant amperage. It can go higher if using pulse settings.
Moose Knuckle 14 is recommended for Mild steel, Stainless steel, Chromoly, Titanium, Inconel and other space grade alloys. It works best on thinner /smaller to medium applications such as header tubes, chassis tubing and flat welding applications.
It is recommended that you keep the diffuser the shape it comes and you remove and reinstall if it gets out of shape. Also it is recommended with all the BIG Diffuser cups that the user start off on low amps to stabilize the arc as to make sure you will not arc off diffuser. If diffuser arcing occurs you will have to clean/Regrind the tungsten. You will not hurt the diffuser on low amps but if arc with high amps you can deteriorate the Diffuser. Also be careful not to drop or hit cups against hard objects being we all know the nature of glass.