Victor 0781-1445 SR4J-540 Professional High Pressure Regulator has been designed for heavy duty applications and for larger cylinders. Ideally suited for pressure vessel and dead-end testing. Delivery pressures up to 4500 PSIG on some models. This regulator features a machined brass body and housing cap, 2.5 inch brass gauge, cartridge type seat with PCTFE seat, a piston type brass actuation, a Delrin cap bushing for smooth adjustments, and a sintered inlet bronze filter. All SR 4 Series regulator models may be panel mounted, which requires a 1-3/4 inch hole in the panel for mounting. For a flush panel mount installation order one panel mount nut 1409- 0093. For an adjustable panel mount installation order two panel mount nuts 1409-0093.