Constant temperature refrigerators are guaranteed to maintain the USP-quality storage conditions specified for 2-8 degree Celsius refrigerators. These models are factory set to 5°C, and the temperature of the air inside the chamber does not get colder than 2°C or warmer than 8°C. They stand alone among scientific refrigerators in this regard, because most others have air temperatures that vary from 0-10°C during the refrigeration cycle. Such temperature swings are not acceptable when storing small volumes of liquid (vaccines, insulin, and similar pharmaceuticals) because the thermal weight of the material is too small to dampen the effect of wide temperature variations.