Snow Performance Stage 2.5 Boost Cooler, Carb 4150 Flange, Forced Induction Progressive Water-Methanol Injection Kit (Stainless Steel Braided Line, 4AN Fittings)This system uses a progressive controller that proportionally injects more or less according to manifold pressure. Start and full points are adjustable for engagement and delivery curve, to match what the engine requires. Boosted engines can gain performance through cooler intake charges and the large increase in octane and detonation suppression. It can also be geared towards fuel economy and using lower grades of gasoline. Comes with one 4150 style