Made of pine wood with natural finish, the blocks have good smell of pine wood. Each block is smooth sanded with round corners. Including 50 wooden blocks and tracks, 10 glass marbles and a basic builder manual book Marbles run through the cube blocks with slanting holes and channels, and run along the tracks by gravity. Kids can easily follow the step by step guides that shows them how to build tracks, or challenge to create their own tracks, there's endless building possibilities. Encourage basic principles of architecture and engineering, develop spatial awareness, creativeness and imagination Recommended for children aged 4 years and up This wooden marbles run toy construction set include 50 wooden blocks and channels, 10 glass marbles and basic builder manual. Made of all natural pine wood, 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. The uniquely shaped blocks, 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.