Specifications: 1) Material: 34Mn2V, 30CrMo, 34CrMo4 2) Outside diameter: 108mm,121mm,140mm,159mm,219-325mm 3) Water capacity: 1.4L-15L,20L-50L 4) GB5099/ISO9809 Gas Cylinderis transportable high-pressure vessels. It is manufactured with the most advanced technology, machinery and equipment in the world.It is ideal for holding such as oxygen, hydrogen, argon and carbon dioxide. The majority of the Gas Cylinder is made of high-quality alloy steel material. They are widely applied in the chemical, metallurgical, mechanical, medical, scientific research and construction industries.