D'Addario Unicore HU510

Available for cello only, the Helicore/Unicore set is comprised of A and D strings, with cores forged of a single strand of high-tensile steel, in contrast to the G and C strings, which are crafted with the multi-strand core of the Helicores. The solid steel cores of the A and D produce increased power and volume, but keep a clear tone and quick bow response.