Panaracer Fire XC Pro 2.1 Black/Red Steel Bead Zero Slip Grip Natural tread compound integrates more natural rubber to decrease rolling resistance and increase tread wear life A mix of 2, 3, and 5mm center knobs, tall cornering knobs, color stripe on sidewall made of Silica compound for added durability Aggressive, all-around tire Weight: 670g PSI: 35-65PSI