D'Addario EXP12 with NY Steel 80/20 Bronze Acoustic Guitar Strings, Coated Medium, 13-56

An ultra-fine layer of EXP Coating is bonded to the 80/20 bronze wrap wire which is then wound onto the hex-shaped core wire. The result is a built-in barrier against the corrosion and wear that can quickly sap the life out of your strings and your sound . EXP 80/20 Bronze strings have a natural round wound feel and extra-bright tone that lasts three to four times longer than traditional guitar strings.