Wide Link Design 105 Double Front Derailleur For Increased Rigidity & enhanced Shifting Response For Use With 105 St-5700 Or Ultegra St-6700 Shifters Only For Optimum Shifting Performance Wide Inner Link Increased Rigidityand Takes Front Shifting Performance To A New Level, Especially Under Heavy Load For 10-Speed Drivetrains Light Action Spring Reduces Effort Required To Actuate Shifts Maximum Capacity Of 16 Teeth With 50-56 Tooth Outer The Aluminium Parts Arecoated To Resist Corrosion & Maintain Their Great Looks