Tech Master 5 Port Two Stage Diaphragm Cylinder Regulator FKM (VITON) Seal - for O2 and Inert Gases- Inlet <=300 Bar BS 341 No.4 - Outlet 0-3.5 Bar G3/8 BSP L/H Brass Male. Model No. GPT401-04-03-01-0 (GAS1040)