Dean Markley Blue Steel Bass Guitar 5 Strings Light 45-60-80-100-125 The unique Cryogenic treatment realigns the molecular structure of the string, giving Blue Steel more highs and lows, a longer life, and a greater ability to stay in tune. Blue Steel strings are the world's first and finest Cryogenically-processed strings. Blue Steel strings are a total breakthrough in string technology. Starting with the very finest quality materials, Blue Steel strings are frozen to minus 320 degrees Fahrenheit, then held there for an exact period of time. Finally, they are slowly and carefully brought back to their original temperature.