Pirastro Passione Viola C:

Passione is the gut string with increased stability. The sheep gut core of the Passione strings is manufactured, wound, and polished in the traditional way: by hand. Passione strings possess a fascinating diversity of sounds, which allows musicians to alter their tone as desired. The core sound is full, round, and warm and has a complex overtone spectrum causing brilliance and clarity and a great power of projection.