Stirling Ultraguard™ -70°C Phase Change Material
Safeguard your biological materials from temperature excursions, no matter what, with Stirling Ultraguard.

What is Stirling Ultraguard?
Stirling Ultraguard sealed bricks are filled with non-toxic PCM that changes phase at -70°C and is exclusively designed to extend ultra-low temperature (ULT) passive holdover time for up to eight hours when conditioned and placed inside of a ULT25NEU portable ULT freezer.
Now your high-value biological assets can be further protected when unpowered, for longer...
- If electric power is not available or lost unexpectedly
- In remote locations where stable, continuous power is unavailable
- During limited-range transport of temperature sensitive samples
- For replacing dry ice with a reusable and safer alternative

Combining Stirling Ultraguard with the ULT25NEU supports contingency planning and safe storage of temperature-sensitive biological materials, virtually anywhere and regardless of power, infrastructure, or dry ice availability.
Phase change material (PCM) bricks back up and extend -80°C to -60°C passive holdover time for up to eight hours inside the Stirling Ultracold ULT25NEU portable freezer.