For the initial reveal of the vehicle, fill the cylinder with water and swirl the car around until the water changes color! Take it out of the water to reveal the amazing designs! Change the car's appearance again by dipping it in warm water and then change it again by dipping it in cold water! Repeat over and over to keep changing the designs. It's like having two cars in one! The cylinder does double duty - it's not only the perfect tank for dipping, but it also serves as storage! Color Reveal cars are designed for use on Hot Wheels tracks, so kids can explore and create unlimited storytelling possibilities, with lots of Hot Wheels action, through inventive car play.