This is the lightest and strongest 520 Quick Change sprocket  conversion kit on the market.

Kit is complete with a chromoly steel drilled front sprocket, heat treated steel rear sprocket or AFAM hard anodized alloy rear sprocket, AFAM black hard anodized billet alloy quick change sprocket carrier, premium D.I.D. heavy duty 520ERV3 gold X'ring race chain cut to length and a rivet style connecting link. Rear sprocket hardware is included.