1. This rear disc brake caliper lower pump is specifically designed for 50 - 150cc all - terrain vehicles (ATVs), go - karts, and off - road vehicles. Its unique design allows it to be well - adapted to the corresponding models, providing precise and efficient braking support for the vehicles. It is a good option for vehicle modification. 2. In terms of materials, it is made of semi - metallic materials. Semi - metallic materials have excellent wear resistance and stability, and can withstand high - intensity friction and pressure. They can ensure good braking performance under various complex road conditions and driving conditions, ensuring the safety of the driver. 3. Whether on the exciting go - kart track or in the challenging off - road journey, this brake caliper lower pump can play an important role, providing reliable support for the vehicle's braking system. 4. It is an accessory that improves the performance of 50 - 150cc all - terrain vehicles (ATVs), go - karts, and off - road vehicles, and is favored by users in regions such as Africa, Europe, South America, Southeast Asia, North America, Northeast Asia, and the Middle East.