The full name is stainless steel tube string fin surface cooler. The principle is to let the hot medium, cold medium or refrigeration working medium flow through the inner cavity of the metal pipe, and the gas to be processed flows through the outer wall of the metal pipe for heat exchange to achieve the purpose of heating or cooling the gas. The purpose of string fins is to increase the heat exchange area and improve the heat exchange effect. Stainless steel finned surface coolers are required in the case of copper corrosion or when the working temperature is relatively high. http://www.tlw-heatexchanger.com/product/stainless-steel-fin-surface-cooler