Modular hubs with a variety of axle conversion options. Forged, CNC machined 6061 aluminum shell, sealed cartridge bearings. International Standard 6-bolt disc rotor mount. Front: includes convertible endcaps to switch between 9x100mm QR or 20x110mm thru-axle. 215g/475g (stub axle options allow front to convert to nutted 3/8" or 14mm fixing see Halo adapters). Spin Doctor hubs also sold in Halo Combat, SAS, Tornado, Freedom wheelsets see BTI wheels.