The Ernie Ball Beefy Slinky Electric Strings are ideal for guitarists who like to detune their instrument to lower tuning combinations. This is ideal for the lovers of metal worldwide to give your guitar the optimal gauge combination for Drop D & Drop C tuning. They are manufactured to the highest standards to ensure quality optimum performance and longevity. The wound strings are made from nickel plated steel wire that is wrapped around a hex shaped steel core wire. This ensures a well balanced tone when playing.