1/2" RP threads, 5 psi max, with limiter. Maxitrol’s 325 Series regulators are used in residential, commercial, and industrial applications. The 325 Series features a high-leverage valve linkage assembly to deliver a lockup characteristic. As a result, the regulators can precisely control from full flow down to pilot flow. Suitable for natural, manufactured, mixed gases, liquefied petroleum gases, LP gas-air mixtures, and DIN EN 437 gas families 1, 2, and 3.