This premium solid core string is made with a high polymer nylon, giving it a crisp response. The core is surrounded by a thin metal film for added power, and the coating has a silicon treatment in order to help the strings snap back on contact. With its great all-around playability and high comfort level, this is a very solid option for non string breakers. Gauge: 16L/1.25 Length: 39ft/12m Composition: Solid Core (high polymer nylon w/metallic film) Color: White w/silver coils Yonex Tennis String YDW125