PHCbi brand TwinGuard Series upright and chest freezers provide twice the sample protection for double the peace of mind. Two independent refrigeration systems offer a circle of protection unmatched in the marketplace. Performance down to -86 C is based on integrated complementary refrigeration circuits, robust cabinet design and intuitive smart controls and monitoring. TwinGuard Series freezers are ideal for safe, long term storage of your most high valued products, such as stem cells, embryos, cell lines, rare specimens and other biological materials.