Learn about the forces of gravity with the Teifoc run N roll marble run! designed to promote creativity, ingenuity, and innovation in young minds. Teifoc is a unique build and play system that uses real reusable bricks to create fun and elaborate structures and creations. Bricks are made of cooked clay and are safe for play. Each Teifoc kit includes one or more building drawings, but you can let your imagination create in endless ways! safe Soluble sand and corn-extract based mortar creates castles and landscapes. To build a new model, simply soak in water, dry the bricks and start again. Its as easy as that! Teifoc is designed, engineered, and manufactured by Eitech in Germany.