ACOUSTIC GUITAR STRINGS MEDIUM LIGHT: .011 .015 .022w .030 .040 .050 DR Strings EXTRA LIFE phosphor bronze acoustic strings are the same string as their popular RARE's except for one very important detail. EXTRA LIFE's are made from phosphor bronze wrap which has been coated with a super thin advanced .0003 inch coating applied before winding. This coating includes a corrosion inhibiting lacquer for extra protection against damaging substances such as sweat, dirt, grit, grime, humidity, and "acid hands". "Big deal," you say, "Everyone has a coated string these days." True, but the big difference here is that DR is the only manufacturer who also coats the plain strings with the same .0003 inch coating. DR-EXR11$11.54 String Coatings for Longer String Life