The cycling headset top cover has an outer diameter of 1 1/4” (31.8mm), fitting most standard bicycle headset stems. Its precise size ensures a secure fit and stability.Made of aluminum alloy, the cap is strong yet lightweight. It features a stylish finish that enhances its look, while also ensuring easy installation and greater durability. And the M6 stainless steel bolt offers excellent corrosion resistance.Suitable for mountain bikes and road bikes, this accessory enhances both functionality and appearance, making it easy to upgrade your bike's style.Replace the original cap with this cap with bolts when using. Make sure it is securely fastened.Check compatibility with your bike's headset stem before installation.