A. The fixing screws for the brake levers of this mountain bike are made of metal, specifically titanium alloy. They are sturdy and durable, providing reliable support for cycling. B. Their specification is M5x25 hexagon socket screws, and each pack contains 2 screws. This reasonably - designed specification can be adapted to various mountain bike models, such as Guide R, RS, and RSC hydraulic disc brakes. There's no need to worry about compatibility issues during installation. C. In terms of usage, they are mainly used to fix the brake levers of mountain bikes. With these screws, the brake levers can be more firmly installed on the bike, ensuring the normal operation of the braking system and greatly improving cycling safety. Whether cycling on flat city roads or through rugged mountains, they can play an important role. D. In terms of quality, these screws are finely made and of good quality. Their titanium alloy material has high strength, is corrosion - resistant, and can withstand relatively large pressure and friction. They are not easy to damage even after long - term use, providing protection for cycling. Choosing these brake lever fixing screws means choosing a worry - free and reliable cycling experience.