Description: This is a DIY assembled pumping unit toy. After assembling and turning on the power switch, the product will run. DIY pumping unit toy is very good experimental toys, because children can understand the integration and application of industrial knowledge, physics knowledge, and multidisciplinary knowledge during the hands-on process. It is made of wooden. High simulation industrial prototype structure, overall internal structure assembly, real reproduction of pumping process, cognition of petroleum industry machinery, fusion of geological and cultural knowledge. The length of this DIY pumping unit toy is 22cm, the width is 17.8cm, and the height is 9cm. The pumping unit mainly use crank-rocker mechanism to transform the rotating motion into reciprocating motion, and the oil is eventually extracted from underground to ground through the pumping device. It is a great educational toy for parents and children grow together, cultivate the spirit of artisans, guide innovative thinking. Item Name: DIY Oil-Pumping Machine Material:Wood Batteries: 2 x AA Batteries (Not Included) Size:17.8cmx9cmx22cm/7.01inx3.54inx8.66in Notes: Due to the light and screen setting difference, the item's color may be slightly different from the pictures. Please allow slight dimension difference due to different manual measurement. Package Includes: 1 Set of DIY Oil-Pumping Machine Kit