VERSATILE STRINGS – Designed for optimum playability, D’Addario’s Helicore violin strings are one of the most versatile stranded-steel core strings available. Helicore strings suit many playing styles, levels and instruments. STRANDED STEEL CORE – Helicore violin strings are crafted with a multi-stranded steel core, giving them great playability and a clear, warm tone. Smaller string diameter provides quick bow response while quality materials and workmanship create pitch stability and longevity. FOR 4/4 SCALE VIOLIN – Scaled to fit a 4/4 size violin with a playing length of 13 inches (328mm), these medium tension strings are optimized to the needs of a majority of players. The E string included with the H310W set is a plain steel E (tin-plated high-carbon steel) with no winding. BUILT TO LAST – Packaged in uniquely-designed sealed pouches, Helicore strings have unparalleled protection from the elements that cause corrosion. MADE IN THE USA – D’Addario leverages centuries of string-making experience and advanced computer-controlled winding technology to bring you the most durable, consistent and long-lasting strings. All D'Addario strings are designed, engineered and manufactured in the USA to the most stringent quality controls in the industry.