Internal gear 3speed hub: for use with any IS 6bolt disc brake \n Rotary gear selection with no protruding indicator chain or switch box \n 6061 aluminum hub shell with 13/32" slotted solid axle (215mm overall axle length) \n Gear ratio range of 177% (33% each step) \n Includes 3spline 18 tooth cog and a SLS30T twist shifter