UNIVERSAL COMPATIBILITY: Four different colour of light up track cars can attract kids attention and make them feel happy. Each of them is compatible with most of bend and flex race track sets, including dinosaur toys track,rainbow tracks and so on(the inner width of the track should be at least 2.2 inches) .Safe and Easy to Play - These magic track extra cars are made by environmentally friendly non-toxic plastic materials, which are safe for children. For these magic racing tracks cars, the switch are at the bottom or on the top. The child can easily use it independently and have fun Each Toy Car requires 2 AA battery (NOT included).We suggest you to purchase the rechargeable battery to save battery cost .Funny DIY Stickers Included- Children can decorate their cars with funny stickers, which is suitable for the transparent car body, making the car attention-grabbing and special .Best Gift for Kids -Different colour of light up track cars can attract kids attention and make them feel happy. Parents can interact with kids by choosing one of the cars, and act as a driver of three different functions. It can not only be enhanced family relationships, but also educated children about traffic safety by these track cars .