Marshall Excelsior ME318P Pol Adapter Full Flow Marshall Excelsior Full Flow POL Adapter The ME318P POL Adapter is machined of solid brass The 1/4 inch male pipe fitting fits the inlet of all standard low pressure regulators The POL nut features a left hand thread and fits all standard LP gas cylinder valves Caution: when installing the 1/4 inch Male NPT into regulator inlet, it is recommended that Teflon tape be used instead of the thread Sealant If thread sealant is used