This is a good, inexpensive 520 steel conversion kit for your GSX-R. 

Each kit is complete with:

• one Superlite chromoly steel front sprocket
   
• one black Superlite heat treated steel rear sprocket
   
• one RK 520XSO series X'ring sealed chain (cut to proper length)
   
• one a rivet style master link. 

The average mileage on each kit is 17-20k miles if everything is maintained and lubed properly.