... :20T Top gear:42T Front derailleur1.Index front derailleur,top pull2.Suitable for triple chainwheel,steel clamp3.Clamp diam:ø28.6mm,ø31.8mm4.Capacity ... pars,such as:frame,front fork,wheel,steel balls,chain,pedal,front brake,rear brake,brake lever,v-brake,derailleur lever,handlebar,grip ... BICYCLE,tricycle and so on. Looking forward your ealy reply. Front derailleur