The large one fits the rear crank and seals the rear main bearing. The smaller fits the crank nose and seals the timing chest cover. The oring fits the front crank behind the timing sprocket. I bought one of those kits. It was described as "universal". I guess it has all the seals for the 700 ,750 & 850. I assume I'll end up with a lot of funny looking gaskets that don't fit anything on my bike...hopefully it's got all the ones i DO need.