In the DR tradition of using old style construction to improve modern performance, PURE BLUES electric guitar strings are designed with pure nickel wrap wire, round wound upon round cores. While this is a slow, expensive method of string making, it does produce a string acclaimed for 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 string. Sounds great on any vintage guitar!!