Synthetic core, 2 sizes. Medium tension.
All strings are ball end, full size, medium tension unless specified.
Possibly the worst D-string I have ever tried.
Pros: I like Warchal's packaging with the "re-usable" inner plastic bag.
Cons: Grainy, loud and metallic sounding. Prone to make crashing noises if you dig in.
Other: Both my violas have approximately around 37,5cm vibrating string length.