This is the aftermarket replacement upper carrier roller at the top of the undercarriage that supports the weight of the track from sagging.
This carrier roller is designed to fit the Takeuchi TB 175 and TB 180 models. The blue arrow in this image helps to guide you to the location for the installation of this top roller. There is no additional hardware required for installation, simply unscrew and remove the existing roller and replace it with the new roller. This carrier roller is guaranteed to fit and you can see both a side and top view of the roller above to verify you are looking at the correct piece. Please call us if you have any questions.