the first two rollers of a 3 roller mill has a wide gap to break the husk from the grain, then it passes between the second and third roller to crush and separate the husk from the grain. Makes a more uniform crush.
It has bearing races in it as opposed to a solid brass bushing so it runs smoother and will last a lot longer.
It's throughput is also quite a bit faster than the barley crusher, one of the bigger reasons for getting it. Milling 50LB of grain takes a while in the barley crusher.
It's a heavy duty monster that I've always wanted.
Same grain mill Shiretown uses in their brewery.