These are treat yourself luxury support stockings including Tactel climate effect technology ensuring breathability in wear, a sheer appearance & velvety touch whilst perfectly hugging the contours of the leg. RAL Compression Class 1, 18-21mm Hg The advanced technology used in the manufacture of this range has been proved to increase elasticity to aid ease of application to the leg.' As Used by the Whiteley Clinic, The Pioneering Vein Clinic' Properties Breathable Tactel climate effect wicks away moisture, so ensuring excellent comfort in wear. Extremely elastic Easy to put on because of the flat stress/strain curve of the knitted fabric. Comfortable Material & visual elegance ensure optimum comfort in wear. Always remember to buy two pairs, one to wear one to wash. Always consult a Medical Professional before wearing Compression Support hosiery.