D'Addario Helicore Violin Single A String, 4/4 Scale, Heavy Tension 4/4 scale violin with a playing length of 13 inches (328mm) Heavy 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