Carbon Molecular Sieves (CMS) are a type of material used in gas separation processes. They are made from a form of activated carbon with a high surface area and a uniform pore size distribution. CMS is commonly used in Pressure Swing Adsorption (PSA) systems to separate gases such as nitrogen, oxygen, and hydrogen. Carbon Molecular Sieves works by selectively adsorbing gas molecules based on their size and polarity. The pores in the CMS are sized to allow small gas molecules, such as nitrogen or hydrogen, to pass through while retaining larger molecules, such as oxygen or carbon dioxide.