Interconnecting hardware/components allow DIY construction Kit shows off basic features of a four-cycle internal combustion gasoline engine Made w/ durable plastic Battery operated (batteries not included) Let your kid get their hands on this DIY mini replica of a classic four-cycle internal combustion gasoline car engine! This intuitive, engaging gadget allows children to play around with the valves, cylinders, cranks, and pistons all in one kit. It also delivers powerful action using the provided cables and battery pack distributor for nonstop fun!