Phillips 66 Megaflow AW 46 is a mineral based lubricant that is used in Hydraulic Systems. Megaflow is a line of Phillips 66 Lubricants that are premium hydraulic fluids with outstanding oxidation resistance. "AW" signifies that this fluid contains zinc anti-wear additive to protect hydraulic pumps from premature wear. 46 represents the thickness of the oil which is an International Standards Organization Viscosity Grade (ISO VG) 46.