This wooden marbles run toy construction basic builder manual.The marble run construction set is ideal on many levels Kids can design their own track and launch marbles into it for hours of building and playing fun.which stack like any other building block, have specially designed slanting holes in them perfectly sized for marbles to speed through.Children can enjoy learning basic physics principles and develop spatial awareness, creativeness and imagination, and the basic principles of engineering and architecture.Contents : A Wooden Marbles Run Game Toy With balls.