Fairly Odd Treasures White with Indicating Blue Silica Gel, 5-Pound 5 Pound Sack of White With Blue Indicating Silica Gel Beads Great for refilling Air Compressor Desiccant Filters, Machinery using large volumes of Desiccant, Etc. Silica Gel beads are .5-1.5MM in size Contains:White 90% & Blue 10% Indicating Silica Gel Beads Mixture The blue Indicating beads will turn from Blue to Pink when the Silica Gel absorbed with moisture