The S3 sintered compound is optimal for street bikes, dual sport, touring, cruisers. It's recommended on applications with rather larger engines or for people who ride harder than average and want the great stopping power of a sintered brake pad. Fits: Suzuki GR650X 1983-1988 GS450E 1988 GS550E 1980-1982 GS550L 1980 GS550M KATANA 1981-1983 GS650 1980-1982 GS650G KATANA 1981-1984 GS650GL 1981-1982 GSX1000S KATANA 1981-1984 GSX1100 ESD 1980-1983 GSX1100 ET 1980-1983 GSX1100 EX 1980-1983 GSX1100 EZ 1980-1983 GSX1100ES 1983 GSX1100S KATANA 1981-1984 GSX400E 1985 GSX400S 1985-1987 GSX750S KATANA 1982