The Hot Wheels color-changing vehicles in a 2-pack are full of surprises. The container includes two 1:64 scale Hot Wheels color-changing vehicles with a special color-changing coating. For the first color change, fill the container with water and swirl each vehicle around until the water changes color, then remove the vehicle. Cool designs will be revealed. Want to activate the color change effect again? Fill the container with cold water, dip each vehicle in, and watch the color change. Warm water reverses the color change effect. Kids can switch back and forth between warm and cold water as many times as they like. It's like having two vehicles in one. The container serves as a dipping pool for the vehicles but can also be used for storage. Each 2-pack is sold separately. Color and design may vary.