D'ADDARIO'S POPULAR JAZZ LIGHT GAUGING WITH AN EXCLUSIVE SEMI-FLAT SURFACE-. CENTERLESS GROUND STAINLESS STEEL DELIVERS ROUND WOUND TENSION WITH A FLATWOUND FEEL. CENTERLESS GROUND STAINLESS STEEL DELIVERS ROUND WOUND TENSION WITH A FLATWOUND FEEL. ENVIRONMENTALLY FRIENDLY, CORROSION RESISTANT PACKAGING FOR STRINGS THAT ARE ALWAYS FRESH. MADE IN THE U.S.A. FOR THE HIGHEST QUALITY AND PERFORMANCE. STRING GAUGES: PLAIN STEEL .012, .016, STAINLESS STEEL .024, .032, .042, .052.