The FuelTech FT450/FT550 6 Cylinder Universal A Harness is designed for use in 6-cylinder engines. It's great for professional mechanics who need a reliable wiring solution for engine upgrades, as well as DIY enthusiasts looking to enhance their engine performance. This harness is a plug-and-play option, which means it can be easily installed on engines with a standard setup. It's resistant to moisture, heat, and oil, so it can withstand tough conditions. It has all the necessary connectors, relays, and fuses built-in, and is compatible with nearly any application that has 6 injectors and 6 coils. Overall, it's a versatile and durable wiring solution for 6-cylinder engines.