Seeking to provide guitarists and bassists with a new voice, Cobalt 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 Slinkys are also soft and silky to the touch with perfect intonation. Gauges .050, .070, .085, .105. Part number 2732. Cobalt provides a stronger magnetic relationship between pickups and strings than any other alloy previously available.