Gentec 452 Series Designed for medium to heavy duty gas welding, cutting, and heating applications, 452 Series is a Harris style regulator with a 2-3/4in diaphragm and a Victor style seat mechanism. 9/16in-18RHM, Gas: Oxygen.Features: 2in gauges for easy reading Stem-type seat assembly for more reliable performance Forged brass body Chrome-plated housing cap for fuel gas and oxygen models Self re-seating external pressure relief valve on oxygen, inert gas, CO2 and nitrogen models Sintered bronze inlet filter Weight: 3 lbs UL listed