GSX1300 Hayabusa & B-King 1999-2012. GSX1100 & Katana 1980-1987. GSX750 & Katana 1980-1983. GSX1000 Katana 1982. You are buying a single Downpipe Header exhaust gasket. If you need more than one which most bikes have then change the quantity above to as many as you want maybe 1 or maybe 4 or even more for spares.