Sharing same state-of-the-art features as the FASTR, the FASTR REACT adds distinctive rows of paddle-like serrated shoulder treads designed to better "lockdown" the tire during hard acceleration to more efficiently transfer the power of each pedal stroke into forward momentum. React faster out of the gate with the FASTR REACT. - CYLEX 120 TPI Ultralight casing - UTC Rubber Compound - Folding Bead