We do have a lot of different stacker available on the market since 100 years…
If we look carefully those tools do work under specific conditions:
-Should be deer hair or similar stiff hair.
-The amounts of hairs are defined.
What I create, is a stacker what can accept all kind of hair, furs, fibers, hackles (including soft ones) and that, whatever the amount you want to use.
As well the nice thing is that you can benefit all magic tool features/advantages (mixing different color together or/and different material such as natural fibers and synthetics fibers).
So this is a very flexible tool.
On top of that, as we often need to clean up fibers tangled, that tool included a groomer and a plucker.