Wide Link Design 105 Double Front Derailleur For Increased Rigidity & enhanced Shifting Response For Use With 105 St-5800 Or Ultegra St-6800 Shifters Only For Optimum Shifting Performance Wide Inner Link Increased Rigidity & Takes Front Shifting Performance To A New Level, Especially Under Heavy Load For 11-Speed Drivetrains Long Pull Arm For Light Action Spring Reduces Effort Required To Actuate Shifts Maximum Capacity Of 16 Teeth With 46-53 Tooth Outer The Aluminium Parts Are Coated To Resist Corrosion & Maintain Their Great Looks