Supersprox - Counter Shaft Sprocket for KTM 950/990/1090/1150/1290Fully lightened with radial holes. Ultra hard surface layer reduces friction to prevent power loss caused by chain drag. Grooved teeth maximize sprocket life by preventing dirt build up. Made from SCM 435 Carbon Free steel and carbon impregnated. Made in Europe The refined core structure ensures that the teeth will not break when worn, like cheap C 45 sprockets. Specifications Material Steel Chain 525 Over All Thickness 16. 5 Spline ID 25 Spline OD 28