Features Features Metzeler's CKB design (Continuous Knob Binding) with dense, narrow knobs that dig into soft terrain and an extended footprint on hard terrain Provides superior grip in an incredibly wide variety of terrain, adds braking stability and boosts tearing resistance on mid-hard and hard terrains Alternated diamond-shaped and shovel-shaped lateral knobs for optimal directionality and steering feel Parabola-shaped center elements: the center of the knob digs, the sides withstand the stress and enlarge the tire's footprint 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# 0312-0344