I picked up a couple of nested colander/bowl combinations
just did this today myself...
it's kinda hard to compare tumblers, when they rate them by pounds of rocks... as I was cross referencing models, I found the 3-4 lb drums are about 1/3 the size of my RCBS tumbler, so I need to be 9-12 lbs to be of similar size ???
I looked for Rosen locally today & couldn't find any... thought about applying some spray adhesive to the wheel, & see if that helps with the slipping ???