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 new lesson on how a simple machine works. This large wooden tow truck teaches children how to use wheel and axle technology by cranking the handle in the front of the truck bed to watch how the pulley works by raising and lowering cargo. Use Unit Blocks (sold separately) with this Block Science Big Truck to teach simple machine and STEM concepts while encouraging construction, deconstruction, teamwork, social interaction and self-expression. Measures 15.25”H x 5.5”D x 11.25”L.