D.I.D. (DKK-013 520VX2 Steel Chain and 14 Front/45 Rear Tooth Sprocket Kit Fits: Kawasaki EX250 Ninja 250R 08-12 D.I.D Chain Model: 520VX2; Chain Color: Steel; Chain Length: 106; Gearing (Front/Rear): 14 tooth/45 tooth D.I.D's Patented X-Ring design has the best sealing properties of any O-Ring chain; D.I.D X-Rings keep the dirt out and lubrication in for the longest wear life The X-Rings twist between the side plates instead of being squished to reduce friction and minimize power loss High carbon steel rear sprockets are heat treated for maximum durability and long life; Countershaft sprockets are made from chromoly steel for superior strength and durability