D'Addario's heaviest 80/20 Bronze gauge, EJ12's offer heavier tension resulting in a bolder, more resonant acoustic tone with higher resistance for heavy strumming and flat-picking. Extra-bright tone mixed with deep and projecting bottom end. 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 0.013, 0.017, Bronze Wound 0.026, 0.035, 0.045, 0.056.