Rims are continually bombarded by extremely hot particles discharged by braking surfaces; the most destructive of these are iron-based. Being very hot, they embed themselves in the rim surface by melting their way into the clearcoat. As they accumulate, these particles form an increasingly rough surface that dirt and grime readily adheres to, thus making the rims progressively harder to clean. Bilt Hamber auto-wheel is a fast-acting wheel cleaner, designed to clean even the filthiest of rims without the need for any agitation. In fact, it's formulated to offer the same level of cleaning power as highly acidic wheel cleaners, but without any of the associated safety risks. Highly acidic wheel cleaners work by attacking iron-based particles and reducing their size, which releases them from the rim surface. They are certainly effective, but they also attack the underlying rim substrate if the clearcoat is compromised (e.g. by kerbing or stone chips). Bilt Hamber auto-wheel works differently, by using a potent neutralised acid salt to render the iron-based particles water soluble, thus enabling them to be rinsed away. Powerful biodegradable surfactants complete the process, by dissolving and lifting away residual dirt and grime.