Item DescriptionEPS, Electronic Power Shift, electronic front derailleur. This front derailleur requires specific, separate Athena EPS Interface and Power Unit, battery pack, and shiftersSpecial materials throughout offers the best stiffness and weight possible Athena features an alloy outer cage and alloy motor and gear housingWaterproof, high over torque motor-gear box creates solid, ultra fast, under load front shiftsAutomatic repositioning/trim depending on the rear cog selectedBraze-on fits frames with pre existing front derailleur braze-on mounts. Carbon braze-on mounts use the front derailleur stiffness increaser, CP-93297. *Specific EPS band-clamp adapters are also available use CP-95107 for 31.8mm or CP-95109 for 34.9mmItem Specificationsrings: doublespeed: 11spclamp: braze-on*capacity: 16Tmin/max: 34/55Tcolor: black: