Exxon HyJet IV-A plus is an advanced fire-resistant phosphate ester hydraulic fluid designed for use in commercial aircraft hydraulic systems where phosphate hydraulic fluids are recommended. It is the best-performing Type IV hydraulic fluid built on the strengths of its predecessors. HyJet IV-A plus is characterized by high temperature stability, low density, and outstanding rust protection. All of these fluid characteristics will contribute to lower maintenance and operating costs for airlines. It is superior to all other Type IV fluids in these respects. Exxon HyJet 4-a plus meets the specifications of all major aircraft manufacturers and SAE AS1241.