A cryo vial, or freezing tube, is a specialized container designed for the long-term storage and preservation of biological samples at extremely low temperatures. Typically made from high-quality polypropylene or glass that can withstand freezing conditions, these vials are equipped with leak-proof, secure caps to prevent contamination and evaporation. They are often used in cryopreservation to store cells, tissues, or other samples in liquid nitrogen or ultra-low temperature freezers.