CHUJO302 is made of solid brass rod with a stainless steel nozzle, specially compounded seat and diaphragm. Heavy duty 1/2" CO2 (.825-14) CGA nut and tailpiece with sintered bronze strainer are standard on LP, MS, and MV series. All models have 1/4" male flare backchecks. Each pressure range has its own spring for proper balance between inlet and outlet pressures. Operating gauges available with 0 to 30-60-100-300