CEP Progressive Running Compression Socks feature graduated medi compression, air channels, Achilles tendon protector, anatomic foot padding, comfortable top band and an extra-flat toe seam. Odor-reducing silver ions, microfiber technology, breathable construction and moisture management, all lead to a more comfortable running experience. Why compression? Every muscle cell needs energy in the form of oxygen. Oxygen is transported to the muscles via the blood, so the better the blood flow in the arteries, the better the muscles are supplied with oxygen. This supply can be positively influenced by compression. CEP compression socks carry a 30 day guarantee that ensures you are happy with the fit and the wear of your socks. If not, return them within 30 days and receive full credit. In addition CEP guarantees that their products will will hold the proper compression for six months providing the garments are cared for according to the wear and care instructions.