D'Addario Pro-Arte Violin String SetDAddario Pro Arte Strings have a synthetic core and produce a warm, mellow tone. They are exceptional strings for serious students and amateur players. Pro Arte strings are less sensitive to humidity and temperature changes and break in quickly. Lower tension maximizes bow response and playability. E Steel with ball end A Aluminum on nylon D Aluminum on nylon G Silver on nylon String orders are shipped in 4 4 size and medium gauge unless otherwise