Synthetic/Hydronalium wound.
Warchal Brilliant strings offer a brilliant, rich tone and wide dynamic range. They offer concert-hall projection across all four strings.

Features: 

• Advanced synthetic core string.
• Brilliant, rich tone and wide dynamic range.
• Full projection across all four strings. 
• Quick tuning stability. 
• Suitable for intermediate and advancing students.
• The sound of the synthetic A string matches the set perfectly, in comparison to traditional metal core A-strings.