Time To Run Cushioned Coolmax Running Socks Lycra ankle cuff contains excellent stretch properties to help prevent the sock sliding down. Terry pad provides protection against both impact and abrasion. Y Heel construction-provides a better fit for optimum comfort and performance. Support zone containing lycra which helps the sock to remain in place and giving a firm, supportive fit around the arch of the foot. A flat toe seam to help prevent blisters.