The kit consists of some baffles (can't remember how many I had to put in-2 or 3 maybe-I'm not where the BX is at this moment) and either some sheet metal screws or short nuts with bolts to mount them to the underside of the MMM deck. The baffles prevent the clippings from blowing out the chute. Instead they (if dry & not overly long) float around in the eddies of air current around the blades and get a vegematic type experience. You must also have the 3 mulching blades but must order these separately. The holes in the baffles were ALMOST perfectly aligned, yet not quite. The baffles required a little "persuasion" from my sledgehammer to get everything into good enough alignment for all the screws/bolts to fit. The system works amazingly well for me, though not everyone who posts here has had as much success as I, as you can see if you scroll down this thread:
