– Wheel cleaner ideal for maintenance of N gauge (9mm) powered vehicles- The cleaning effect of a special sponge (conducting cloth), which has both the property of conducting electricity and cleaning performance, gently and cleanly removes dirt from the wheels.-The driving wheels can be easily polished by letting the driving wheels idle on the energized mat through an electric current.** If the conductive fabrics become dirty, please purchase the separately sold “RWC-01 Replacement Conductive Fabrics for Wheel Cleaner Soft-kun N/Z Scale (2pcs/Set)”.