Thunderblack is a set made with three different types of synthetic elastomer. In the third and fourth strings, the density of the elastomeric material is also increased by adding micronized metal iron powder during the extrusion phase.
This technological solution allows for the same working tension to have smaller diameters, greater volume and sustain than any type of polyurethane and silicone rubber strings available on the market. The Thunderblacks ensure fast and stable intonation. Thanks to the metal powder there is also a great slipperiness of the fingers.