Halo announces perhaps the finest track hubs out there. custom machined with the distinctive Halo sweeping centre curved shape.Japanese sealed bearings.Hollow axle with Ti colour finish.C clip on both side of each sealed bearing.Hi-polish custom CNC machined hub shell, Alloy flush fit bearing cover and end cap.120mm spacing.Laser logo.32H, 36H or 48HDouble fixed or fixed/free options.C-L 31mm / C-R 31mmDiameter 62mm.Note: General Fixed cog check: for correct fixed use, the fixed cog should Never move on the hub when pedal force is applied in both directions. i.e. if the cog moves, then something is wrong. Continued use with a fixed cog that moves will result in damage to the hub.Important Note : Threads for \"Fixed Cog Lockrings\": Our hubs must only be used with ISO standard 1.29\" x24TPi L/H fixed cog lockrings. Do Not Use French (1.32\" x 24TPi) or Italian (33 x 1mm) standard lockrings. The larger diameter French and Italian lockrings may appear to work. but. will strip the threads from the ISO hub.