Allows you to attach a -6 AN hose fittings directly to your factory NA 5/16" hardlines. A tool is included to cut your fuel hardlines back to whatever position you'd like to convert to AN lines. We recommend under the car just before the firewall. If you'd like to run a complete AN line configuration we recommend adapters available in our Fuel Delivery section. The NB will only use one of these fittings as it's a dead headed or non-return style fuel system.