?Sturdy Construction? The U511 Locomotive is made of sturdy 4mm thickness birch plywood by laser cutting technology, precise and clean. The wood is eco-friendly, safe, recyclable, manufactured from natural materials and no glue required to assemble them. | ?Mechanism? The ingenious design allows you to get a close-up view of the gear systems and drive wheels in action using a miniaturized linkage of rods and cranks. Featuring mechanical parts, the model has the power and energy to travel up to 20 feet when it