This is a complete ATI / Procharger Stage II 3 Core Intercooled Supercharger System with a P-1SC head unit and stock 6 rib pulley setup for the 1996-1998 Ford Mustang Cobra 4.6L (4V) which will get you a 60-70% horsepower gain on just 8 psi of boost! When ProCharger developed the ultimate supercharger system for the high compression, highly-sophisticated 4.6L 4V engines, the goal was simple: maximum performance and reliability with minimal cost and maintenance. The results speak for themselves. This system is 100% complete, including handheld programmer, fuel system and tuning for stock vehicles or those with a catback only, just bolt on and drive! If you have other modifications such as headers, midpipe, camshaft, etc. then look at the Tuner kits.