Pirastro Obligato Violin String Set (with Gold E)Pirastro Obligato Violin Strings feature an exclusive new core material made with advanced manufacturing techniques resulting in the proven sound of gut strings with the advantages of a synthetic core. E Gold, ball or loop end A Aluminum D Silver G Silver String Features: Core made from a modern synthetic multifilament fibre Warm and full sound with a brilliant, rich overtone spectrum and focused tone Excellent playability and response throughout the