Therma-Weld Upper - Ultralight construction blended from TPU, mesh, and Alcantara materials with minimal stitching for the lightest, strongest overlay available. * Medium / Soft Flex Pattern * Dual lace zones for pinpoint adjustment all over your foot. * Integrated TPU Ankle Strap - superior hold, pulls your foot into the "heel pocket" * Lux Chassis - our lightest & most rigid chassis ever, maximum comfort, response, and no heel / toe lift.