This is the aftermarket replacement idler for a GEHL CTL70, CTL 75, and CTL80 compact track loader. The Gehl CTL undercarriage parts are interchangeable with the comparable Takeuchi and Mustang models.
This idler is the larger roller wheel towards the front of the undercarriage, closest to the bucket. See the image with the blue arrow indicating the idler location. For a full Takeuchi TL 150 parts diagram click to the main Takeuchi TL150 category to see the undercarriage parts locations.