The SuperGrindz 6 Pack 2-1/2” 60mm x 22mm XL Heavy Duty Brake Hub Cleaning Pads are specifically engineered for use in commercial truck, bus, RV, and trailer applications, designed to work with 22mm studs. These pads are compatible with Pro-Graad XL and Counteract Hub Pro XL holders (HBCR22, HBCTK-22), making them suitable for over 90% of commercial truck wheel end components. This refill pack includes six 2-1/2” diameter (60mm x 22mm) SuperGrindz XL Hollow Center Quick Change Heavy Duty Brake Hub Replacement Cleaning Discs, but does not include the holder tool. The hollow center design allows the discs to slide safely over and around wheel studs, protecting the stud threads during use. For optimal performance, it is recommended to operate at low speeds, below 5,000 RPM, in a forward (clockwise) direction. These heavy duty cleaning pads are highly effective in removing rust, corrosion, and debris from brake hubs, ensuring the integrity of the wheel and hub surfaces without excessive material removal or gouging. Made with aluminum oxide technology, the discs feature a durable rust-eating mineral embedded in a non-woven nylon web, which provides high conformability and minimizes chunking while delivering efficient rust and corrosion removal. These pads are an essential tool for maintaining clean and safe wheel surfaces in heavy-duty commercial applications.