The core material of this string is a high-tensile "rope" made from carbon steel, which is then wound with chrome steel.
It is reportedly an outstanding set for arco, as it can withstand a powerful and heavy bowing arm. It has a brilliant sound with a short sustain, with great projection and "big tone volume." The strings are very stable and should be instantly playable. They have a very quick response, which is slightly quicker than Pirastro's Original Flat-Chrome.
Since we're not as personally familiar with these strings, our descriptions of them are primarily based on manufacturer information, but we're happy to add more info as we discover it -- and feel free to Email us your experiences with them!