Ernie Ball 2720 Cobalt Power Slinky Electric Guitar Strings are a perfect match for those who like chunky rhythms for rock and roll or blues. Power Slinkys have long been favored by Slash, Metallica and Kenny Wayne Shepherd due to the thicker gauge combination providing a slightly more powerful tone. The Cobalt Series is clearly an improvement on its classic nickel-wound counterpart giving the player increased sustain, clarity and output. In addition, they resist sweat and moisture better and have unmatched flexibility when compared to other nickel wound strings. Cobalt is the most magnetically active string alloy on the planet and attracts the magnets in your pickups more than any other string.