Edelbrock Performer Nitrous Systems #71003 is the best way to get a major power increase in your 2002-08 Subaru WRX. The nitrous system interfaces with the OE fuel system and increases fuel flow to the existing fuel injectors when the system is armed and triggered. The Nitrous Systems listed below include: 10-lb. nitrous bottle (shipped empty, powder coated silver finish unless noted otherwise), brackets, steel braided hose, filter jets, fittings, switches, hardware and owner's manual for a complete install. This system that is capable of an 50 horsepower increase.