This product is designed as a failsafe in case your water-methanol system is not functioning properly. The included pressure switch monitors pressure between the W/M pump and the injection nozzles. If the W/M system is not making proper pressure (due to a failed pump, broken line, etc.), the included LED will alert the driver of an issue. The switch can also be wired to your aftermarket EFI system or electronic boost controller to automatically cut boost, retard timing, etc. Includes a user-adjustable W/M pressure safety switch (35-100 PSI), a Snow Performance Water Methanol pressure gauge, a high-intensity LED, and an inline adapter manifold for -4an lines.