Ugears Model MARBLE RUN CHAIN HOIST KITMarble Run Chain Hoist wooden 3D puzzle from Ugears What is it about marble runs that makes them so compelling? Kids (and adults!) can watch marbles going down a track, passing through various obstacles, for hours on end. Marble runs are fascinating, they grab our attention, and yet they're also relaxing. Marble runs and races have become an unexpected YouTube phenomenon, with thousands of videos racking up millions of views. You choose a marble to