Features: 4pcs/set ukulele strings, 3 colors for option(black/ white/ colorful). High-quality nylon material, giving you clear and bright sounds. B string: 0.56mm/ 0.022in, F string: 0.71mm/ 0.028in, D string: 0.81mm/ 0.032in, A string: 056mm/ 0.022in. Great replacement for your old ukulele strings.