more air flow, keeps mog above the chaffer = little to no tailings no stalk tops go in hopper, as did with air foil chaffer and long tooth chaffer change individual panels in the chaffer assemby to exactly match the crop harvested = chaffer isn't removed between say corn and wheat, just change panels more capacity due to better controlled air flow, nothing but clean grain in hopper clean grain sieve is open to 60% as all it does is control the air flow to chaffer There are two sizes for corn, if very high moisture should use the larger hole inserts.