Product Specs: Front wheel hub for a 5/8" axle. Adjustable with spacers (not included) Allows wheel hub to spaced out from the brake rotor, without the rotor location moving Rotor hub specs: - (4) 5/16-18 threaded holes on a 3" bolt circle - 5/8" ID High Speed Bearing (held in with c-clip) ~Works with all 4 bolt MCP Rotors Wheel Hub Specs: - American Bolt Circle (3 bolts holes on a 2.50" circle) - Dual bolt pattern for both 1/4" & 5/16" bolts - 5/8" ID High Speed Bearing (Pressed In) ~Works great with VanK Split Rims