A simple aluminum alloy stem. # 6061 – T6 aluminum alloy forged koramukuranpu Diameter Φ 28.6 mm sutakkuhaito 45 mm (125g hbn10600) The item color, about Size Item Color May Vary Depending on the type of display, actual product may vary slightly from the product image. This listing for the specification, improved the design of the logo, etc., may be altered. In addition, the manufacturers to reveal the answer your questions about the dimension and a personalized fit and you are not the actual product. Thanks for your understanding.