Take your racing speeds to new levels of fun with this Hot Wheels Track Builder 2-Speed Power Booster accessory. Built for lasting durability, this accessory connects easily to your existing Hot Wheels track. As a result, you can incorporate it into any original, elaborate track design. Designate your choice of two speeds, and watch your cars accelerate up to three times their speed as they whiz through the battery-powered booster. The booster offers a speed advantage during competitive racing or everyday play.