D'Addario J65 Ukulele Strings, Soprano D'Addario's most popular ukulele set known for warm and long lasting tone Optimized for Soprano Ukuleles tuned to traditional ADF#B tuning Clear precision rectified nylon ensuring that the roundness and dimension control of each string are unsurpassed Rectified Clear Nylon, Non-Ball End Made in the U.S.A. for the highest quality and performance