Wilkerson® by Dixon® High Flow Regulator, High Pressure Self-Relieving Standard, series: R40, 2 in NPT/BSPP-G, 1200 scfm, 0 to 180 psig Adjustable, 32 to 150°F, Zinc. Wilkerson® by Dixon® R40-0CRHG High Pressure Self-Relieving Standard High Flow Regulator with GC230 Gauge, 2 in NPT/BSPP-G