Material: This wooden puzzle made of wood, durable and safety for children use.Use: After the assembly is complete, press the battery switch, when the gear touches ground, the trolley rotates backward with the gear, and when the pinion gear touches ground, the trolley travels forwardFunction: Exercise children's hands ability and understand the principle of gear transmission.Educational Toy: This gear shuttle car could used as a teaching aid the classroom to stimulate children's learning interest and curiosity.Easily Assemble: Follow the instructions to assemble without glue and other tools, you could enjoying DIY. Specification: Material: wood Size Chart: Finished:145cmx52cmx55cm/57.09inchx20.47inchx21.65inch & ; Package Includes: 1 Wooden Puzzle Kits Note: 1.This is not infant toy, please take away from children to avoid eating.2.Please allow slightly errors due to manual measurement and different monitors.