The frame of this lightweight balsa wood toy tri-plane is easily assembled (instructions included). The other parts (solid hardwood base, vertical support, brass arm, pivot, solar panel) are supplied complete – no assembly required. The solar panel is so efficient and the pivot and overall balance so perfect that, when assembled, the electrical power generated by a sunbeam coming through a window (or a simple low wattage light bulb) will keep the propeller turning steadily all day (or all night if the bulb is left on). Very calming and soothing to the psyche, and highly recommended for all in our high velocity culture. Almost hypnotic, it makes you smile. WARNING: CHOKING HAZARD. Toy Contains Small parts. Not for children under 3 yrs.