MIL-PRF-5606H Hydraulic Fluid. Red, mineral base. X/C 5606H Aviation Hydraulic Fluid is a red-dyed, mineral-based fluid formulated to provide protection under severe-duty applications. X/C 5606H meets military specification MIL-PRF-5606H for use where "super clean" hydraulic fluid is desired. Filtered and hermetically sealed, it is excellent for use where "super clean" fluid can help prolong service life and reliability. The superior additive technology provides excellent low-temperature fluidity as well as exceptional anti-wear capability, oxidation and corrosion inhibition, and shear stability.