I have a brand new set of Vortex sprockets. They are 520 w/ 15t front and 48t rear. The rear is aluminum and the front is steel. The rear is the new CAT5 style and the front is steel. They are for KAWASAKI bikes. I bought them off CL and thought they would fit my SV or Speed Triple, but no go. My loss, your gain. If you know someone who has a Kawa or want to make some $$ reselling them, hit me up. Thanks!