Aquila Strings AQ-21U Nylgut"Low D" Baritone Ukulele Strings New Nylgut series strings Set of 4 baritone ukulele strings; two wound strings, followed by 0.88mm and 0.67mm Low D tuning - DGBE Strong, consistent sound; Aquila strings produces a better sound than nylon and is not so metallic Made of Nylgut, a special synthetic material that has the same specific weight as regular gut strings