Adamas 1818NU, String Set for Steel-string Guitar, Thickness: Gauges .012, .015, .023w, .032w, .044w, .053w, Coated Nuova version, Solid brass ball-end, With E6 and A5, core and coil with identical diameter, Composite gauging: A5, G3, and B2 strings are thinner than the gradations of other manufacturers, High-End premium phosphor bronze, Ultra-thin nano-coating less than 1 micron = 0.001 mm is applied to the winding wire and core before the string is wound, Special alloy with higher copper content, Warm, rich, earthy sound, New environmentally friendly packaging - shrink-proof protected