For thoroughly mixing paint or any two-part material that needs to be mixed. Attach to a hand drill and blend pigment powders evenly. Has facets built into the rod for better chuck locking.
Double-opposed helix for quick and uniform mixing. Just go easy on the speed to start or you could be wearing it.
STL was too large for Thingiverse, so uploading PLY
I recommend 100%, but you could get away with less