Ernie Ball 2223 Nickel Super Slinky Guitar Strings - Buy 10, Get 2 Free Gauges 9-11-16-24w-32-42. Made from nickel-plated steel wire wrapped around tin-plated hex-shaped steel core wire. They produce a well-balanced all-around good sound. Ernie Ball replacement strings are precision manufactured to the highest standards and most exacting specs to assure consistency, optimum performance.