Building upon the multi-faceted early childhood development benefits of unit block play, each sturdy wooden truck in the Block Science Big Truck series is designed to overlay a new lesson on how a simple machine works. This large wooden tow truck teaches children to use wheel and axel technology to raise and lower Unit Blocks. A child may place the Unit Blocks in the crane and crank the handle in the front of the truck bed to watch how the pulley works. Unit Blocks and these accompanying Block Science Big Trucks teach simple machine and STEM concepts while encouraging construction, deconstruction, teamwork, social interaction and self-expression. Dimensions: 5.5" L x 15.25" W x 11.25" H (14cm x 38.7cm x 28.5cm). Suggested Age: 3+.