Castrol Hyspin? AWS is a high quality solvent-refined mineral oil based hydraulic fluid, treated to inhibit oxidation, foaming, and corrosion. Castrol Hyspin? contains anti-wear additives for use in high-rated hydraulic pumps and motors, and meets the requirements of all major hydraulic component manufacturers. Hyspin? offers a long oil life due to its excellent thermal stability and resistance to oxidation. Good water tolerance and demulsification characteristics allowing rapid separation of condensation and/or water contamination.