Hope evopro 4 os spacer kit conversionthis os spacer kit makes your 15x110mm pro 2pro 2 evopro 4 boost hub compatible with 15x110mm boost forks that use the sramrockshox torque cap interface these caps will ensure youll enjoy quicker and simpler wheel fitting and the stiffest and most responsive steering out there features converts hope pro 2 pro 2 evo or pro 4 boost hub to a sram torque cap15mm axle compatible with rockshox forks with torque cap fitting only hope part number