Warchal Brilliant 16"-17" Viola Set - Medium Gauge Full Viola String Set For 16"-17" Viola Medium Gauge A String: Synthetic Core - Hydronalium Winding - Ball End | D String: Synthetic Core - Hyronalium Winding - Ball End G String: Synthetic Core - Stainless Steel/Pure Silver Winding - Ball End | C String: Synthetic Core - Stainless Steel/Pure Silver Winding - Ball End