Expansion Lane Change & Extension (Straight & Wave) Set for Mini 4WD Japan Cup Junior Circuit (White)The Tamiya Expansion Lane Change & Extension Set is a must have for Mini 4WD enthusiasts. This set allows you to upgrade your racing tracks with lane changes and extensions, creating more dynamic and challenging circuits. As you assemble the components, you'll enjoy the satisfaction of designing your own unique track layout. Whether you're a beginner or an experienced racer, this set enhances your racing experience by adding complexity and excitement.