1. This bicycle head tube cap is designed for mountain bikes and road bikes, suitable for fork steerer tubes with a specification of 28.6 mm. It is made of a combination of aluminum and steel, perfectly combining the lightness of aluminum and the sturdiness of steel. This not only reduces the unnecessary weight of the bike body but also ensures strength and durability during use, making your ride more relaxed and smooth. 2. Whether you are facing the rugged challenges of mountain biking or pursuing speed on the road, this head tube cap, with its good compatibility and decent quality, can provide reliable protection and stable performance for your bicycle. 3. It can fit tightly around the steerer tube, effectively preventing dust and debris from entering, thereby extending the service life of the bicycle fork components and keeping your bicycle in good operating condition. 4. Choosing this bicycle head tube cap means adding a guarantee and comfort to your riding experience.