Pairing the focused high and low-end presence of the Skinny/Heavy combo with a newly conceived iron/cobalt alloy wrapping which extends string life and tonal spectrum alike, the Ernie Ball 2730 Cobalt 7-String Skinny Top Heavy Bottom Strings are some of the most harmonically-rich strings on the market.

• Sizes - .010, .013, .017, .030, .042, .052, .062
• Cobalt-plated steel wire wrapping for extended range
• Made in southern California with environmentally friendly packing