Optimal for Detuning. Ernie Ball Not Even Slinky strings are perfect for those who like to detune their instrument to lower tuning combinations. Metal fans around the world have turned to the Not Even Slinky set to give their guitar the optimal gauge combination for Drop D and Drop C tuning. These strings are precision manufactured to the highest standards and most demanding specifications to ensure consistency, optimal performance and long life. Not Even Slinky wound strings are made from nickel-plated steel wire wrapped around a hexagonal-shaped core steel wire. Unwound strings are made from specially hardened and tin-plated high-carbon steel, producing a balanced tone for your guitar. Caliber .012.016.024p.032.044.044.056