Alice Ukulele Transparent Nylon String Set Pack of 5sets Fit for ukulele greatly,sound fantastic, and stable last a super long time. The ukulele strings are in the material of nylon. B - Clear Nylon .022" 0.56mm; F# - Clear Nylon .028" 0.71mm; D - Clear Nylon .032" 0.81mm; A - Clear Nylon .022" 0.56mm. The string is packaged in the plastic bag as photo shown. Package including: 5 sets ukulele strings.