SRAM Rise/Rail/Roam-Series Axle Conversion. Features: For SRAM Rise-40/60, Roam-50/60 and Rail-50 mountain wheels Rise-40 conversions require separate tool (use part #GS-4593), where Rise-60 conversions are a tool-free design OS-Q/R (31mm diameter cap) conversion is only to be used with RockShox forks due to inside dropout compatibility Specs: Model:X0 Hubs,Roam30/40,RiseXX Wheel:front Conversion Description:9x100mm QR (19mm cap) Remarks:*Does not include freehub bearings, use GS-4548 (freehub assembly)