YoYoFactory's 100% Polyester, 6-ply string.
This string is 100 percent polyester, instead of cotton or blended like most yoyo string. Polyester insures less friction and more durability. We recommend these for advanced level yoyos and those who practice a majority of complicated sleep tricks. It is Type 6 string, which means it is the same width as Slick 6. These strings have a loop at the end of the string already.
NOTE: Do NOT use these strings on YoYos with wooden axles or starburst response systems, as they will wear out quickly and may break during play!