Robotime DIY 3D Wooden Puzzle Marble Run Assembly Model Building Block Stem Toy For Kids AdultAbout this item New wooden marble run! Build it with 294 pieces and 10 marbles. The end result is pretty cool. It has a crank that uses large gears to move marbles up to the top of the machine where they roll down into different channels. Different from other wood puzzles,black grey appearance,metal nameplate and acrylic pieces to make the finished product more visually interesting and allowing the balls to be seen in action more. Great instruction