Uniweld RHT8017 Medium/Heavy Duty Two Stage Hydrogen Regulator with CGA350 Inlet Polished chrome bonnet Easy to read 2 inch single scale gauge 1-5/8 inch tri-layered reinforced neoprene diaphragm (1st stage) 2 inch tri-layered reinforced neoprene diaphragm (2nd stage) Heavy duty mechanical stem type seat and nozzle assembly