These freezers elevate the level of protection by using a redundant cooling system design that provides advanced protection of contents by functioning independently and simultaneously. Each cooling system uses single compressor auto-cascade configurations to provide uniformity and stability regardless of high ambient temperatures. TwinGuard ultra-low freezers are designed for long-term storage of high-value biologicals, including mammalian and plant cell cultures, stem cells, cell lines, and subcellular components. -58°F to -123°F (-50°C to -86°C)