For Soprano, Concert or Tenor Ukulele tuned ADF#B (Low A, or D tuning), or Low G,C,E,A. One silver-tone wound Nylgut string for Soprano, Concert or Tenor Ukulele tuned ADF#B (Low A, or D tuning), or Low G,C,E,A. Please note that it will say tenor Low G on the package, but this string will fit ukuleles ranging in size from Sopranissimo to Tenor. (Just cut off any extra length) Aquila strings are made in Italy of their patented Nylgut material. Nylgut is a synthetic material developed to combine the longevity of nylon strings with the superior tone of gut strings. Nylgut has acoustical qualities nearly identical to that of gut, and is the first truly successful synthetic version of the natural product. Other benefits of Nylgut strings include increased resistance to wear under tension and extraordinary immunity to changes of climate and humidity. Aquila strings are easy to play and have a rich, warm tone. They are a top choice of ukulele players worldwide.