BUILD YOUR OWN ENGINE KIT – The Build Your Own Engine Kits from Machine Works make excellent gifts for vehicle and model enthusiasts who like creating and learning about mechanical systems and engineering. Requires 2 x AA batteries (not included). DIY KITS FOR ADULTS AND KIDS – This functional model of a 4-Cylinder Internal Combustion Engine is the perfect activity for both children (over 10 years) and adults to build together. DISCOVER & LEARN AS YOU BUILD – This model is a simplified 1:4 Replica of a 4-Cylinder Internal Combustion Engine and illustrates the main operating principles and functions. INCLUDES OVER 100 PARTS – This 100+ piece Kit for kids and adults is enjoyable to construct and includes all of the tools you’ll need to complete the operating model. The Fully illustrated step-by-step instructions guide you through every stage of the assembly process. Each component is clearly identified, and each function explained. PRODUCT FEATURES - The transparent engine case of the finished model means the moving parts are clearly visible when it’s operating, allowing you to see the interaction of the crankshaft, pistons, and valves, as well as the illuminating spark plugs., Manufacturer: Machine Works