153IN-125 single stage regulators are designed for heavy duty gas welding, cutting and heating applications. These regulators are ideal to use for steel fabrication, ship building, metallurgical and chemical industries. 2-1/2" gauges for easy reading. 3-1/4" stainless steel diaphragm for accurate pressure delivery. Delrin-cap bushing for smooth adjustments. Stem-type seat assembly for more reliable performance. Forged brass body and housing cap. Self re-seating external pressure relief valve on oxygen, inert gas, air CO2, and hydrogen models. Sintered bronze inlet filter. Steel gauge protectors are color-coded: green for oxygen (GP32X) and red for acetylene (GP32Y) models. UL Listed.