GHS H-10 Hawaiian Ukulele Black Nylon Strings CONCERT OR SOPRANO  These strings will fit your concert or standard soprano sized Ukulele. FRESH SOUND - Freshen up your uke's tone with these black nylon replacement strings from GHS. STURDY NYLON  These strings, like most ukulele strings are made from durable black nylon to ensure durability and crisp sound. GAUGES - 25-32-36-28 Freshen up your ukulele's tone with these black nylon replacement strings from GHS.