The energy-efficient Shuttle Portable Ultra-Low Temperature Freezer from Cole-Parmer offers secure mobile transport of high-value vaccines or biological specimens. Its functionality is suited for biorepositories, medical/surgical suites, pathology laboratories, tissue banks, regenerative medicine and other applications in clinical or diagnostic medicine, research and pharmaceutical distribution. A Stirling engine operates the low-temperature freezer, which requires no compressors, dry ice or LN2, and expends the same volume of energy as a conventional light bulb. The Humm free-piston Stirling engine uses two moving parts that float on helium gas bearings to eliminate contact wear. The linear driver modulates engine power to deliver cooling on demand without on/off cycling. The thermosiphon evaporator freezes contents, and a microcharge of environmentally friendly cooling medium creates a uniform ultra-low temperature via a continuous process of evaporation and condensation within the sealed tube. Weighing 42 lb, the portable freezer is efficient for both benchtop and field uses. A weather-resistant touchpad offers digital temperature display, indicating interior temperature and error codes. It includes temperature presets of -20, -40 or -86 C and a system lock indicator. Users can adjust by 1° intervals. The freezers also feature visual and audible alarms. The unit’s rugged cabinet withstands travel. Its composite vacuum-insulation panels with CFC-free foam protect contents from high ambient temperatures. When not in use, the cabinet can be stored on its side, end or upside down. A double gasket seals the interior chamber and provides dual protection against moisture and heat gain. Molded-in handles are easy- to-grip, and it operates on both AC/DC (12 V) power by simply switching the included power cord.