Back half off a Caterpillar 544. Will fit Fabtek 346B , Cat 544 & Prentice 2346. FAB05 bogie assembly , 600mm tires & rims , frame , center knuckle , drive shafts , center bearing & frame lock cylinder. You can make your 4 wheel into a 6 wheel forwarder. We also have 2 set of bunks for sale.