This shoe was engineered for achieving your personal best. In collaboration with Tommy Rivs , Craft has created the perfect shoe for speed at distance. The extremely lightweight and responsive Pebax™ midsole houses a tuned carbon plate to deliver extreme propulsion and efficiency in every stride. The minimal upper is one-piece engineered mesh and the internal construction allows superior comfort in an ultralightweight platform. • One-piece engineered mesh upper • Pebax Foam™ midsole bottom layer - ultra light , ultra high rebound • Pebax Foam™ midsole insert - ultra light , ultra high rebound • Ultra-light, ultra-thin rubber outsole for fast road conditions • Tuned carbon fiber plate with precision split for torsion and variable energy return • This shoe is made with Craft’s Race Fit. Built for speed and as a result the fit is slight more snug than our regular running fit - snug in this case means slightly more shallow and the toe and slightly shorter in length. Engineered purposefully in order to achieve greater velocity. For those of you that are in between sizes, or that prefer more room, we recommend sizing up.