The PF22 foam cannon has some of the highest quality foam in the world. The secret is largely based in the more dense compression of stainless steel mesh in their Foam Agitator Pads.
All water coming through the foam cannon runs through this piece, so it can occasionally clog with debris from the water source, or clog from soap crystallization if the cannon has been stored for a long period if time without having been rinsed.
Having one or two of these around will come in handy!
These filters are unbelievable. The foam they create is amazing.