D'Addario Helicore Viola Single C String, Medium Scale, Medium Tension Medium-scale viola (body length 15-15 3/4 inches) with a playing length of 14 1/8 inches (360mm) Medium tension Stranded steel core provides optimum playability and produces a clear, warm tone Versatile string that works well for a wide variety of playing styles and instruments All D'Addario strings are designed, engineered and manufactured in the USA to the most stringent quality controls in the industry