Double Decker Spiral! Motion controlled Racing. The way you race is changed forever, the faster you wave your hand, the faster the wave racer will go! Place your hand above the sensor positioned approximately 3-10 cm or 1.2-3.9 inches above sensor . Wave your hand side to side quickly. Car will be activated after receiving at least 15 waves in 5 seconds, maximum speed 9km/h. The track set includes over 70 track pieces and one Wave Racer sensor car. Connect to other Wave Racers track to expand your raceway. Race circuit size set up: Length 95.5cm, Width 49cm, Heighr 26cm. For Indoor use only. Recommended for boys ages 6 years and up.