This longer bolt and bushing kit is designed to allow your Arctic Cat Alpha One, Hardcore or Yamaha Mountain Max front track shock lower mount to pivot instead of bind during shock travel / compression. Not allowing the factory bolt to back out due to binding and causing damage to the threaded boss in your rail. The inner bushing is peened so that it bites against the rail and doesn't pinch against the shock when the bolt is tightened to spec. You apply grease to the bushing during assembly and with the help of the o-rings, it allows the shock to pivot properly rather than twist on the shock body.
Designed for the front track shock lower mount to rail, the kit comes with a longer bolt, washer, stainless steel bushing and o-rings needed to replace your stock parts.
1st picture shows the differences in the 2 options over the stock, much shorter bolt.
Option 1, standard, has the same thread as your factory bolt and allows preventative measures to be taken against failure. Simply remove and replace.
Option 2, oversized, is an over sized bolt kit. You will need to drill your damaged threads and re-tap threads into the bolt hole. This kit is designed for those who have had their rail previously damaged and they want to try to save the rail