D'Addario Pro-Arte Violin Single Aluminum Wound E String, 4/4 Scale, Medium Tension 4/4 scale violin with a playing length of 13 inches (328mm) Medium tension aluminum wound E string Synthetic core produces a warm, mellow tone Less sensitive to humidity and temperature changes, and break in quickly All D'Addario strings are designed, engineered and manufactured in the USA to the most stringent quality controls in the industry