ROKR is a DIY wooden 3D puzzle craft kit featuring mechanical gear system. The kit includes a set of wood sheets with precisely laser cut pieces that assemble together to form the marble maze. This is a marble run model, which is designed in dark gray and dotted with silver. The Marble Spaceport was born with the theme of future space technologies. The uniqueness of this marble run lies in its complex mechanical structures, which are 6 diversion mechanisms and 5 tracks. Turning the handle, you can watch steel balls rolling through different tracks. With the highly transparent PC and PS materials, you can clearly observe the movement of each ball. In addition, Marble Spaceport has an upgraded design with two drive modes, which are manual mode and electric mode. Switch between these two modes as you prefer to get more fun. Assembled size (estimate) : 12.3" x 9.9" x 9.1"