I tried one on a 930F, it did not help in short beans, the beans stand in front of the guard until enough builds up for the reel to catch and flip over the gaurd. Until then the reel shatters the beans. The one thing I do not like is shatterd beans and dirt build up behind the gaurd level with the top of it, and about 10" behnd it. This makes the cutter bar real heavy on the ground. It did held keep some rocks out but if the reel is set low and pitched back it fliped some over the guard.