High technology seat post. Main shaft in cabon fiber, CNC machined parts. Exclusive and patented nut retention system, that makes seat assembly much easier. Diameter: Ø 27,2 - 29,4 - 31,6 mm - 32,4 mm Setback: 22 mm Length: 320 mm (12 1/2 in.) Weight: 199 grams (6 7/8 oz.)