Sized to fit medium-scale viola (body length 15-15 3/4 inches) with a playing length of 14 1/8 inches (360mm), medium tension strings are optimized to the needs of a majority of players. This D string is aluminum wound. Pro-Arte synthetic core viola strings have a warm, mellow tone. They are less sensitive to humidity and temperature changes, and break in quickly. Pro-Arte strings are manufactured at a lower tension in order to maximize bow response, tonal blend and playability. The perfect choice for players seeking a warm, dark tone.