Features Tread features alternated side diamond-shaped knobs for optimal directionality, cornering grip and steering feel, maximum traction in and out of turns and responsive steering with reduced grabbing in ruts Parabola-shaped center elements: the center of the knob digs, the sides withstand the stress and enlarge the tire's footprint Self-cleaning Alternated-cut knobs add to the balance of lateral and longitudinal stiffness, which maximizes grip for traction and braking and provide outstanding durability Reversible tread pattern Tube type (TT) SIZE: 90/90-21 PART# 0312-0343