... class refrigerantR134A R404ASecond-class refrigerantR290/R508BR290/R508B/R14Ultra Low Temperature freezer is produced to use Germany technology by us, it ... good design, and is conformance with oversea ultra low temperature freezer. 1. two compressor cascade refrigerating system; main parts ... for stainlss, can adjust height for three shelves of freezer easily;four gates is to prevent cooling loss; the ...