The water storage vessel is a hot product in our company, which is made of stainless steel 304(we ensure that 8 nickels contained). The polished surface can be used as a mirror. All the accessories have been through rigorous testing to ensure that they are real materials.The inner wall is sprayed by the GAS certified epoxy coating,effectively keep the algae and moss off,and prevent bacteria from regeneration,thus the filter is efficient and durable.