A freeze dryer removes water from a perishable material in order to preserve it, extending its shelf life and/or making it more convenient for transport. Freeze dryers work by freezing the material, then reducing the pressure and adding heat to allow the frozen water in the material to change directly to a vapor (sublimate). A freeze dryer works in three phases:1). Freezing2). Primary Drying (Sublimation)3). Secondary Drying (Adsorption) Select from personal benchtop or upright freeze dry systems. The units are also found with PTFE coating for corrosive samples.