Model 330 heavy-duty regulator allows for gas withdrawal from oxygen liquid cylinders. Its unique design permits inlet pressures up to 3000 PSIG for use on high pressure cylinders. The Model 301 features a brass body, brass T screw bar adjustment, stainless steel diaphragm, 2.5" brass dual scale gauge, one-piece encapsulated seat design with internal filter and PTFE TeflonĀ® seat and Harris' exclusive self-reseating, tamper-proof internal high pressure safety valve. Model 330 has an auxilliary plugged low pressure port. This model is also ULĀ® listed.