Building upon the multi-faceted early childhood development benefits of unit block play, each sturdy wooden truck in the Big Block Science Truck series is designed to overlay a lesson on how a simple machine works. This large wooden truck has a removable articulating trailer with a large wooden crane for maximum mobility. Children can use the wrecking ball to knock down their Unit Block structures, thus developing social, emotional and conflict resolution skills, while learning about simple machine and STEM concepts. Dimensions: 18"H x 5.5"D x 16.75"L.