Problem Solvers Direct Mount Front Derailleur Adaptor for Moonlander 34.9mm clamp w/ shims 34.9mm Clamp with shims for 31.8 & 28.6 55mm offset for Surly Moonlander Works for Shimano and SRAM High Direct Mount front derailleurs Item SpecificationsFront Derailleur Clamp28.6 (1-1/8")Front Derailleur Clamp31.8 (1-1/4")Front Derailleur Clamp34.9 (1-3/8")Front Derailleur ClampHigh Direct Mount 34.9mm Clamp with shims for 31.8 & 28.6