When D'Addario introduced the first phosphor bronze guitar strings in 1974, the manufacturer took acoustic guitar string quality to the next level. Quickly, the warm, assertive and balanced sound spread around the world and eventually became the absolute standard.
The D'Addario EJ18 Heavy Acoustic Guitar Strings for acoustic guitar are made of a core of carbon, wrapped by a wire of phosphor bronze, which gives the US quality product its unique tone that enriches any acoustic style. At the same time, the 14-59 Heavy gauge is the strongest the series has to offer and guarantees the highest tension with robust resistance.
D'Addario A-Guit.Strings EJ26 11-52 Phosphor Bronze
D'Addario A-Guit.Strings EJ16 12-53 Phosphor Bronze
D'Addario A-Guit.Strings EJ11 12-53 80/20 Bronze
Fender Dura-Tone 880L Acoustic Guitar Strings 
Martin Guitars MA530 Acoustic SP Phosphor Bronze Extra Light 10-47