Martin Guitar knows a thing or two about pampering valuable instruments. If you�re looking for some extra protection for your fine guitar, Authentic Acoustic Silked strings are the right choice for you. Martin adding a soft silk wrap to the ball ends of the 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. Available in 80/20 Bronze and 92/8 Phosphor Bronze. Gauges: 11-15-23-32-42-52