Simple aluminum alloy stem. #6061-T6 Aluminum Alloy Forged Column Clamp Diameter: Φ28.6mm Stack Height: 45mm 125g (HBN10600) Product color and size may look different from the actual product depending on your display type. Product specifications, logo design, etc. may be subject to change for improvements. We also cannot answer any measurements or personal fit that are not offered by the manufacturer. Thank you for your understanding.