Rare Metal 2 Four layer fused forefoot for unprecedented support High abrasion, color-shift toe wrap protection Ultra-light military grade monofilament rip-stop upper SuperCritical midsole for insane rebound Thermo plastic mid-foot support shank High density perforated foam tongue alleviates lace pressure Vibram wraptech rubber sole for superior traction Weighing 11.5 oz makes RM2 incredibly light and strong Slim fit (a size larger is recommended for absolute comfort)