Students get hands on with STEM as they build jumbo-size simple machines! From a real-working dolly to a functioning pulley system, kids can design and construct different contraptions—then use them to explore motion, weight, gravity and more. Plus, our set includes kid-friendly materials like predrilled wooden boards and easy-grip nuts and bolts that make construction a cinch! You get 279 pieces; longest board measures 37 1/2". Buckets not included.