Optimized for Concert Ukuleles tuned to standard GCEA tuning- / Pro-Arté Custom Extruded Nylon for highly accurate, laser sorted treble strings / Inspired and guided by D’Addario ukulele artist Jake Shimabukuro / Concert Ukulele, Pro-Arté Custom Extruded Clear Nylon, Non-Ball End / Made in the U.S.A. for the highest quality and performance / Environmentally friendly, corrosion resistant packaging for strings that are always fresh