The Cryo-Safe™ Cold Box provides a convenient means of preventing expensive enzymes and critical samples from warming. This handy unit consists of a molded polystyrene container with cover. It has an internal 12 place support for 1.5mL microcentrifuge tubes. The space surrounding the tubes is filled with a sealed-in material that maintains the low temperature required for safe storage and transport. When the container is taken out of a -20°C freezer it will maintain a -15°C temperature for 1.5 hours, and will remain below 0°C for four hours.