Derived from the now common graduated compression elastic stockings for sports use, they use the same principle as compression therapy with a particular characteristic: exerting maximum pressure at the ankle that decreases going upwards towards the thigh, so as to facilitate the upward return of blood. The compressive force is obtained from the quantity of millimetres of mercury (mmHg), from the quantity of elastic and from the thread count of the yarn, (expressed in "Den" = Denier - unit of measurement that indicates the thickness of the yarn used), used for the manufacture of the structure of the stocking itself. it is worth knowing that in the international case law for this type of garment, elastic stockings that exert pressure at the ankle of less than 6 mmHg are "quite normal" stockings, only more elastic, but without any additional property; while therapeutic stockings can be defined as articles which have a compression force at the ankle of between 6 and 20 mmHg. Sparco COMPRESSION stockings have a class 1 (> 21 mmHg) compression force and are effective in preventing the development of circulatory problems and extremely effective in alleviating the feeling of heaviness and fatigue in the legs.