T4 is completely solar-powered so you never need to buy batteries. Not only will T4 provide your child with a new understanding of solar power as a source of renewable energy, but will also get your kids outdoors for some wholesome fun in the sun. This kit gives your child the option to easily transform between one of four different modes: Robot – walking legs as well as moving wheels, Insecta – 6 walking legs as well as moving jaws, T-Rex - 2 walking legs and moving jaws, and Drill Vehicle – similar to a miner’s driller/drilling bit and moving wheels. If your children are glued to smart-phones, give them an opportunity to acquire solar power knowledge, learn about mechanical transmissions, and get them outside to play. Amazingly, you might find yourself engaged in conversation with your child, thanks to their newly acquired expertise!