Threaded on one side and with a flange on the other side that makes a fixed fit for a 50mm fuel hose mounted with a hose clamp, this filler neck is intended to be used with the Nuke Performance Competition Fuel Cell (CFC) Unit. This setup is installed by being screwed down into the existing fill neck after the fill cap has been removed and is sealed with an ethanol proof Viton o-ring. It utilizes the existing rollover protection. For 50mm fuel hose. No fuel hose or hose clamp is included.