These fit 14-18 models with 1/2" rail slot. This kit inegrages 4th wheel stand offs into the axle holders so track tensioner bolts can be moved to the outside of rails for easier acess like 19+ models. One kit does both sides. Accepts yamaha wheels with 6004 bearing.Also accepet wheels with 6205 bearing if you swap out to the 6304 bearing.
14-18 Axle Holders with 4th wheel stand off set