The Altus FD-M313 front derailleur offers the Dual-Pull technology, so the the shifting cable can be pulled from the top or from the bottom. The adapters allow the use with tube diameters of 28.6, 31.8mm and 34.9 mm. Chain line: 47.5 / 50mm. Construction type/Clamp diameter: Clamp 28,6mm ||| Clamp 31,8mm ||| Clamp 34,9mm ||| Mid Clamp Material: chain guides: chromed steel