Haba Kullerbu White Ambulance With Momentum Motor - Can Be Enjoyed With Or Without The Kullerbu Track System - Ages 2+This Ambulance can be used with most Kullerbu tracks. The cars wheels rest on top of the Kullerbu tracks. Allowing it to traverse the tracks like a roller coaster. Features a momentum motor. A momentum motor allows the car to travel forward on its own. Simply give the car a push along the tracks, or ground, and watch it travel on its own.