D'Addario Phosphor-Bronze EXP Coated

EXP Coated Phosphor Bronze
Round Wound guitar strings provide longer life and increase durability coupled with the brightness, clarity and sensitivity you've come to expect from D'Addario Strings. Here is how it works: An ultra-fine layer of EXP Coating is bonded to the phosphor 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. And since the EXP Coating is cross-linked to the wrap wire prior to winding, the strings sound fresh and bright; the "new string tone" lasts three to four times longer than traditional guitar strings. 
Guitar scale length 25 1/2", 648mm