D'Addario Helicore Cello String Set, 4/4 Scale, Heavy TensionScaled to fit 4 4 size cello with a playing length of 27 1 2 inches (700mm), these heavy tension strings will allow for greater projection and volume potential. Helicore cello strings are crafted with a multi stranded steel core, resulting in optimal playability while producing a clear, warm tone. The smaller string diameter provides quick bow response. Premium quality materials combined with skilled workmanship produces strings known for excellent