D'Addario EJ17 Phosphor Bronze 13-56 Acoustic Guitar Strings, Medium

D’Addario Phosphor Bronze acoustic guitar strings are precision wound with phosphor bronze wrap wire, over a hexagonal high-carbon steel core.
Phosphor Bronze wrap wire provides tried-and-true D’Addario acoustic tone, with beautiful balance and warmth suitable for all musical genres.
Now the standard in acoustic guitar strings, Phosphor Bronze strings were originally pioneered by D’Addario in the 1970s.