This seemed very valuable as I basically needed drum mandrels to attach the sanding drum. Note that there are two different sized wave supports. "States" 12 piece dremel tool drum mandrel - only 6 would fit my dremel, the other 6 were so small they couldn't be tightened. No idea, maybe there is another use for smaller waves. The quality of the sanding drums cannot be compared to the more expensive Dremel sanding drums, which run until there is no more sand on the drum. They fell apart on very soft driftwood after 20 minutes of use. (many of them) - then it's a good deal.