Kalloy Guizzo Carbon 27.2mm x 250mm. One bolt clamp. matte finish Clamp Style: Std RailsDiameter: 27.2mmDiameter: 27.2mmMaterial: CarbonMax Height: 260mmOffset: 30mmSeatpost Color: CarbonSeatpost Diameter: 27.2mmSeatpost Length: 250mmSetback: 30mmWeight: 254g