4oz bottle of genuine Magura "Blood" blue hydraulic mineral oil. This is the fluid Magura recommends for use in their hydraulic clutch systems found on all R1200GS, RT, ST, R, S and also the newest water cooled R1200GS & RT. Not for use on the K1200/1300 bikes (2005 and later) or the K1600 bikes. Also not for use on older bikes which have their reservoir caps marked "DOT4 Fluid". One bottle is enough for one clutch bleed with some left over.