... , different sizes such as 28mm, 38mm, 36mm to match with clutches.Top rail: Optional accessory, made from aluminum alloy, ... Optional accessory, made from aluminum alloy, looks more artistic with cover.Bottom rail and end cap: Made from aluminum alloy, various ... -01material: aluminum alloymodel: yx-zz-02material: aluminum alloy Item: Bottom rail and end cap model: yx-xl-01material: aluminum alloymodel ...