I just received mine. A little disappointed with the build/QC. The movement is somewhat 'gritty', like the filter edges are rubbing against each other when adjusting. My other VNDs have been much smoother.
Can anyone comment? Have you found the same thing with yours? I contacted the dealer and they seem to suggest I was being fussy. Maybe they're right.
Separately, I can't see how the rear ring adjusts. Mine won't budge. Can anyone advise?