The ZEX Classic Purple Nitrous System is iconic ZEX. Onlookerswill recognize the infamous purple bottle as yourace past the competition. This Classic Purple System issure to draw attention and have the crowd talking. The ZEX Dual Stage EFI Nitrous System is more effective than a typical single stage systembecause it gradually adds the nitrous power in two separately controlled stages instead of onebig ?hit? to give you a faster quarter mile ET The first Tunable from 50-300 additional HP; Two separate power stages for maximum traction controll; Fuel Shear Technology injects enrichment fuel directlyinto nitrous plume for better atomization; Active Fuel Control adjusts fuel enrichment in accordance with bottle pressure so you?ll never run too rich or too lean again