SPIROCORE cello tungsten G & C string combo pack Metzler ViolinsThe set Spirocore S31 represents a technical revolution of the early 1950s. Its strings spiral rope core has a much greater elasticity and therefore a higher vibration capacity with less damping than other rope core strings. This design enables strings to move quickly, making them extremely reactive to impulses of the bow. Due to their superb bowing hand agility, Spirocore strings respond exceptionally easily to various bowing techniques for