Each fuel tank is equipped with our state-of-the-art electrical sending unit that is compatible with 35-240 ohm industry standard dash mounted gauges. Vent boss is barbed to provide a secure hose fit. A female, 1/4" NPT 90° withdrawal rotates 360° to aid during the installation of fuel hose. It is recommended that 3% to 5% expansion areas be allotted in all directions when installing tank.Optional parts:PN 300150 tank install kit. PN300110 Tank cradle(hold down) for all TP style tanks PN 040050 tank grouding device. Tanks are constructed from High density cross-link polyethylene.