With 4 large wheels and 20 oversized ZOOB JR. pieces, the ZOOB JR. ZOOMER lets kids build all sorts of vehicles, from racecars to a Lunar Rover. The wheels are notched so they work like gears, and they snap snugly into ZOOB JR. pieces (but still move, so kids can rebuild and modify their creations as they play). This set includes 8 sturdy cards that inspire kids to design their own creations, along with instructions for 8 vehicles and 12 other models.