D'Addario Pro-Arte Cello Single D String, 4/4 Scale, Medium Tension 4/4 size cello with a playing length of 27 1/2 inches (700mm) Medium tension 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