This Auto Meter kit is for the car enthusiasts and builders who are installing a mechanical fuel pressure gauge (or need to remotely mount an electric gauge's pressure sender). The kit includes 4 feet of durable 3AN braided stainless steel line, which is what carries the fuel (or other fluid) to the gauge. It also comes with all the necessary fittings to hook everything up: a firewall pass-through grommet, a 1/8\ NPT female right angle to -3AN male fitting, a -3AN male to 1/8\ NPT male fitting, a -3AN male to 1/8\ NPT female fitting, and a 1/8\ to 1/4\ NPT adapter bushing. This saves you from hunting down individual fittings. It's a complete, high-quality kit from a trusted brand in performance gauges. Makes the installation process much cleaner and more professional.