Ernie Ball 2721 Cobalt Slinky Electric Guitar Strings provide an extended dynamic range, incredible harmonic response, increased low end, and crisp, clear highs. Cobalt provides a stronger magnetic relationship between pickups and strings than any other alloy previously available. Cobalt Slinky guitar strings are also soft and silky to the touch, making string bending a breeze. Gauges .010, .013, .017, .026, .036, .046