Razor Dirt Bike Pit Bike Brake Adapter for MX500, RSF650, MX650 & SX500. Kit includes 1 adapter, washers, lock washers & mini washers for the stock hub bolts. Adapter allows you to mount a standard 4 hole 190mm pit bike break rotor/disc to your stock razor MX500,MX650,SX500 & RSF650 wheel/hub. Comes with needed hardware ** except rotor/disc bolts*** When obtaining your pit bike rotor/disc get the one with bolt included. However we do include nuts & washers to match standard pit bike rotor/disc bolts.