This is a complete methanol injection system with high-capacity pump, 3-quart tank, dedicated controller, and jets and other parts needed for installation. The kit uses manifold pressure to determine when to "turn up the boost" and spray the alcohol/water mixture into your intake system.
Alcohol injection systems work like an "internal intercooler" allowing for lower cylinder temps and helping prevent knock/detonation - which can lead to catastrophic engine failure. Using an alcohol injection system can also allow you to run more boost, thus netting more horsepower!