D'Addario EJ87C sets are designed for use with all concert ukuleles. Each string within this set is made from our bright sounding titanium material and optimized for standard 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.