If you’re looking for some extra protection for your fine guitar, Authentic Acoustic Silked strings are the right choice for you. Martin has added a soft silk wrap to the ball ends of their Authentic Acoustic strings to prevent wear and tear on the bridge and bridge plate as you play. The silk wrap puts a comforting layer of protection in place every time you change your strings. Phosphor Bronze - Extra Light .010 .014 .023w .030w .039w .047w