6523: 2-Pack Darington and Starla Freewheel Monster Trucks Every episode of "Blaze and the Monster Machines" is an interactive adventure! These monster trucks not only race, but they creatively introduce the worlds of science, technology, engineering and math (STEM)! This 2-pack includes some of the most iconic characters from the series: Darington and Starla. They are both free-wheel (no batteries required) and they have high quality grippy rubber tires!