This bag contains both blue moisture indicating molecular sieve and also normal molecular sieve. The blue molecular sieve is a sodium alumina silicate molecular sieve impregnated with an inorganic metal salt moisture indicator. The desiccant will perform as a 4a molecular sieve plus with the additional ability to visually determine when the molecular sieve reaches saturation. When active, the molecular sieve beads are blue, as the beads reach saturation the color changes to beige indicating that the molecular sieve has reached equilibrium capacity and is in need of replacement. While the white molecular sieve is an alkali alumino-silicate in the spherical form. It is the sodium form of the Type A crystal structure with an effective pore opening of approximately 4A. It will adsorb molecules such as oxygen, nitrogen, carbon dioxide and straight chain hydrocarbons. Aromatics and branched chain hydrocarbons will not be absorbed.