RFX Pro Rear Axle Adjuster Blocks (Red) Ergonomically pre shaped and fully vented Ergonomically pre shaped and fully vented knee generously contoured to accommodate all types of knee braces and guards while a massive air intake system cools and protects Forged Ø77 Remove old axle blocks Take the new RFX Axle Blocks and place on swing arm ensuring alignment and bolts are in position