The 80/20 bronze wrap wire on D"Addario EXP13 Custom Light acoustic guitar strings has a micro-fine coating applied to it before it is 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 guitar"s sound. D"Addario EXP strings have a natural round wound feel and extra-bright tone that lasts 3 to 4 times longer than traditional guitar strings. Coupled with D"Addario"s compound-plated plain steel strings, EXPs are some of the longest lasting, most natural sounding coated strings you can buy. Pack of 10 string sets. Gauges: 11-15-22-32-42-52 D"Addario is the world"s largest manufacturer of strings for musical instruments. Many top guitarists won"t play any other brand. Regardless of your playing style, D"Addario has a set that"s right for you.