This application is a Non-Powerlip Sealed Bearing individual roller. If you waited too long to replace the stock part then the frame pin could be damaged. If that's the case, you need this. Greatly improve drivetrain speed and tension accuracy over stock. Low friction material lowers drag without transferring heat. The only sealed racing bearing replacement roller on the market. No other design functions or last as long as TMD's part. Can be used in upper or lower location.