Designed for optimum playability, D?Addario?s Helicore violin strings are one of the most versatile stranded-steel core strings available. Used by professionals and students, Helicore strings suit many playing styles, levels and instruments. They are often preferred by alternative-style and electric instrument players. 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. Helicore violin strings are crafted with a multi-stranded steel core, giving them great playability and a clear, warm tone. The smaller string diameter provides quick bow response while the quality of materials and workmanship craft a string with excellent pitch stability and longevity. Packaged in uniquely-designed sealed pouches, Helicore strings have unparalleled protection from the elements that cause corrosion. Scaled to fit a 4/4 size violin with a playing length of 13 inches (328mm), these heavy 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. All D'Addario strings are designed, engineered and manufactured in the USA to the most stringent quality controls in the industry. Since 1905, D?Addario has been providing artists and players with the tools they need to perform their magic. As musicians ourselves, we have the unique ability to engineer products that inspire other musicians. The D?Addario family?s vision, creativity, passion and tradition have made us the world?s largest musical instrument string manufacturer. We put our family?s heart, soul and love for making music into every string and instrument accessory we create, and we never stop inspiring performance.