These D'Addario EJ35's are silk and steel light gauge strings for 12 string guitars and are silver-plated copper wound. They have a warm, mellow tone and a soft feel for folk and finger style playing. They are excellent for all 12 string acoustic guitars and are gauged 011-047. These are the string of choice for top professional players around the world. D'Addarios have long been my personal favorites. They may become yours, too. Try a set and see for yourself why so many amateurs as well as professionals prefer D'Addario strings on their guitars.