D"Addario EJ87S sets are designed for use with all soprano ukuleles. Each string within this set is made from our bright sounding titanium material and optimized for GCEA tuning.D"Addario Titanium Ukulele strings are crafted from a dense monofilament material that has an attractive, translucent purple hue and a polished, smooth feel similar to nylon. This unique material is particularly beneficial to Ukulele"s due to its slightly brighter tone and increased projection, resulting in more volume, clarity and dynamics.D"Addario, the world"s largest manufacturer of musical instrument strings, is known as The Players Choice with a reputation for unsurpassed quality and consistency. D"Addario"s innovative packaging reduces waste and provides protection from corrosion. All D"Addario strings are manufactured in the U.S.A. using proprietary, digitally controlled, state-of-the-art machinery for unmatched performance, set after set.