DR Strings Pure Blues Pure Nickel Wrap Round Core 11-50 Gauge: Heavy Pure Nickel Electric Guitar Strings wound on Round Cores Totally Real Vintage String Increased sustain, vintage tone and great low tones for playing rhythm to lead The extra step of winding pure nickel around a round core gives the Pure Blues a punch that players say they are surprised to get in a vintage style string It designed with pure nickel wrap wire, round wound upon round cores