Shinko 540 Series Mud/Sand Rear Tire (Sold Each) 120/100-18 The 540 is designed for extremely soft terrain, such as mud and sand. Wide spaced knobs shed mud quickly and its tall aggressive tread pattern offers increased traction in the nastiest of conditions. For extremely soft terrain (mud/sand) Wide spaced knobs shed mud quickly Tall aggressive tread pattern for increased traction in the nastiest conditions