Perpetual KId Pre-School Education DIY Solar Powered Ferris Wheel Wooden Puzzle Toy DIY Solar Kits London Eye Shipping time around 7-21 days. 21*15.5*20.5 cm (finished product) Slight light needed to drive the wheel ,Monocrystalline silicon solar panel,Plywood DIY design--no extra tools are needed. These plywood Solar Toys only need weak sunshine to make them work. Good for the family--fostering children's creativity and love of science. Also, it is good for kindergarten and schools for organizing solar kits competitions