Marshall Excelsior Full Flow POL Adapter. The ME318P POL Adapter is machined of solid brass. The 1/4in 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 1/4in Male NPT into regulator inlet, it is recommended that Teflon tape be used instead of the thread sealant. If thread sealant is used, extreme caution should be taken that no thread sealant gets in the regulator inlet. FF POL x 1/4in MPT assembly, 7/8in hex nut, packaged.