The "D" on the hosiery stands for "Denier," which translates to "thickness." Each pair of stockings is marked with a number of "D's" to indicate how thick they are.

The smaller the "D", the thinner the stockings; The higher the D, the thicker the stocking. "D" is also the fiber size unit, the larger the number, on behalf of the weight of the fiber, the thickness of the stockings also increases, the smaller the "D" number, the thinner and more transparent the stockings, the more durable socks "D" number is generally higher

0D  15D 30D