Slightly conical with a straight knurled pattern round the top. Level indicator on top and all the way down. Seems to be about 9 mm diameter. Supposedly 6 mm D-shaft.(?) Here’s a picture:
I’ve found some that look similar on Syntaur but no measure or material details. Wanted diameter: 11-16 mm.
Although there’s no level indicator line on the side, the knobs on Roland FA 06-08 look really nice. I’d post a picture but I’m not allowed to post more than one it seems. Are they rubber and about what diameter are they?
Any input is highly appreciated