This is the legendary flatwound jazz guitar string! A list of its players reads like a Jazz Hall of Fame, and it?s still the undisputed king of flatwounds, for many of today?s jazz greats. A true flatwound (not a ?ground wound? or ?compressed wound? like some of the pretenders) with glassy smooth polished nickel winding on a round core, it has the perfect balance of fundamental to overtones required for traditional jazz. Some players claim that its mellow, powerful tones actually improve with age!