Shimano Deore HB-M618/ M615/ M590/ M525A Front Hubs6-bolt ISO disc mounting surfaceDouble contact sealingSuper polished bearing races for low friction rollingItem Specifications Left61Weight304Hub Drilling36Front AxleQR x 100mmHub/Brake Compatibility6-Bolt DiscCenter to Flange, Right33Center to Flange, Right61Flange Diameter,Defined ColorBlackColorBlackFlange DiameterFlange Diameter