Cleartone Monster Heavy Series Nickel-Plated Drop C Electric Guitar Strings Gauges: 13-65 Designed specifically for alternative tunings such as Drop D, Drop C and Drop C#, Cleartone Monster Heavy sets feature heavier gauge strings for that extra tension you need At one micron thin, the "No Feel Coating" EMP Treatment is then applied to all 6 strings to ensure longest tonal life without compromises Monster Heavy Series are heavy duty, but with 3-5 times the lifespan Designed specifically for alternative tunings such as Drop D, Drop C and Drop C#, Cleartone Monster Heavy sets feature heavier gauge strings for that extra tension you need