This string was originally developed as an alternative to the current 'A' string for the Brilliant cello set. Warchal had been concerned that the synthetic 'A' string might be too fragile. However they solved the issue of the synthetic string durability and the metal core version started to take on a life of its own. It was tested by many players worldwide and the results were unexpectedly good. They therefore decided to add it to the range as a separate string.