You've probably seen Zoot's Ultra 2.0 CRx Socks on some of the world's top triathletes. Why? They provide numerous benefits. Zoot consulted doctors in the field of medical compression and came up with a circumference-based fit system so you not only get the perfect fit, you get the right amount of compression. The result is CompressRx graduated compression technology which surrounds your muscles to help stabilize them, increasing response and reducing vibrations and micro-damage that lead to post-exercise soreness. After exercise, these socks reduce edema and encourage blood flow back to the heart which flushes lactic acid. Constructed of a nylon/spandex blend, these left- and right-specific socks also boast anti-blister NanoGLIDE yarn in the heels and toes, plus antimicrobial SilverTECH for odor-free protection. You'll also appreciate the Achilles tendon support, padded heels and toes, and compressive arch support.