EARTHWOOD EXTRA LIGHT 80/20 BRONZE ACOUSTIC GUITAR STRINGS - 10-50 GAUGE ERNIE BALL EARTHWOOD 80/20 BRONZE ACOUSTIC GUITAR STRINGS ARE MADE FROM 80% COPPER, 20% ZINC WIRE WRAPPED AROUND HEX SHAPED BRASS PLATED STEEL CORE WIRE. THESE ACOUSTIC GUITAR STRINGS PROVIDE A CRISP, RINGING SOUND WITH PLEASING OVERTONES. GAUGES .010, .014 .020, .028, .040, .050