The A- and D-strings have a core made from a single filament of high-tensile steel and are wound with chrome steel. The G- and C-strings have a rope core wound with tungsten. The A- and D-strings are brilliant and bright sounding. The G- and C-strings provide a warm and powerful sound and have a short decay. Pirastro Permanent strings have a very quick response with exceptional tuning stability and immediate playability. They are suitable for electric or electrically-amplified cellos.