Stone Polishing drum defects
The 50 and 200 drums had serious defects at the seams. The material was puckered up. This left some of the segments pushed out. The camera angles don't really reflect what you can feel with your hand. This drum would be jumping all over and would damage the stone.
The seam goes from the bottom of the drum to the top. It is raised up for most of the distance.
It is not as obvious on the brown drum but you can tell quite clearly on the black drum by the variation in the pattern as well as the profile of the bottom.