The document discusses refrigerated incubators used for applications such as BOD determinations, plant and insect studies, and bacterial culturing. It describes key features of SHEL LAB refrigerated incubators including a temperature range of 20 degrees below ambient to 45 degrees Celsius, a hermetically-sealed compressor, adjustable shelves, and an interior outlet. Specific models discussed are the SRI3, SRI20, and SRI27 which vary in size and bottle capacity.