Aquila Nylgut strings started a revolution in 1997 when they were released, following a long and difficult process of research and development. Enjoying the feel and, crucially, the sound of genuine gut strings, Nylgut does not suffer from the problems of tuning and longevity associated with gut strings. Gut strings are extremely vulnerable to changes in humidity, and break much more easily than other core materials! Aquila Nylgut strings solve both these problems and yet offer exactly the same acoustic properties. These are a great choice for all uke players and highly recommended! Aquila nylgut ukulele sets are all made from totally innovative materials, discovered and perfected at Aquila's Italian laboratories after a long period of research and testing carried out on the newest synthetic materials. Soprano ukulele set, key of C 1st(G) 2nd(C) 3rd(E) 4th(A)