3 years & up. Building upon the multi-faceted early childhood development benefits of unit block play, this sturdy wooden truck 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 structures. Use Unit Blocks (sold separately) along with this Block Science Big Truck to teach simple machine and STEM concepts while encouraging construction, deconstruction, teamwork, social interaction and self-expression. Measures 18”H x 5.5”D x 16.75”L.