The usage of 40D : 1.Circular knitting, 2.Weaving, 3.Stocking, 4.Hosiery Detailed ... product is hi-performance bare spandex yarn, 15D,20D,30D,40D,70D,105D,140D,210D,280D,420D,560D,840D,1120D,1680D ... .Usage: Covering core, air interlacing yarn, circularly knitting, warp knitting, weft knitting, stockings, covering with cotton, medical bandage, baby and adult ...