Expand your knowledge of the fundamental laws of motion while constructing your own motorized marble run. Explore the fascinating world of physics and mechanics as you have fun building and experimenting. Our kit offers the perfect opportunity to playfully and educationally unlock the secrets of motion. Contents: base, spiral track, back plate, handwheel, front plate, motor, rail connector, motor cover, rail lock, battery cover, 2 gears, drive wheel, 8 metal balls, 2 connection caps, 5 screws. Not included in the set: 1.5V AAA battery and a small Phillips screwdriver. Product size (cm): 6.3 x 21.5 x 24. Packaging size (cm): 21.5 x 24 x 6.3.