I ordered a rear sprocket for my 2001 GSX-R 600 only to find out that I needed a longer chain . I just ordered a 520 kit for the bike so I no longer need the sprocket. The sprocket has never been used only bolted to my tire once, when I found out it was to big to fit with my chain. It is a rear aluminum Sprocket Specialist sprocket for a 525 chain with 48 teeth. I paid a little over $55 for it and I'm willing to let it go for $40 because it was my own dumb mistake. I know this sprocket will fit other bikes makes\models you can check out http://www.sprocketspecialist.com for applications it is a type C rear aluminum sprocket. I'm trying to sell it locally because I really don't feel like dealing with ebay for a $40 item. I have included a pic of the actual sprocket.