This Hypro D403 Repair Kit is compatible with the Hypro D403 and D403GRGI diaphragm pumps and it fixes pumps with mixed oil in the crankcase. If the oil is milky grey in color, then you have mixed oil in the crankcase. If the oil appears mixed, you probably have a hole in at least 1 of your diaphragms, so stop using the pump because if Hypro diaphragm pumps have mixed oil in them for a long period of time, it will destroy the pump. The D403 kit comes with 3 Desmopan Diaphragms (9910-800085), 6 valves (9910-1889050), 6 valve O-rings (9910-1140450), 6 valve O-rings (9910-1260420), 6 valve cover O-rings (9910-780050) and 1 sight glass O-ring (9910-390180).