This 3-in-1 excavator with hydraulically controlled arm is assembled from 168 parts. It can be easily converted from an excavator to a crane or log loader. Step by step, a small assembly is created by simply plugging together. Finally, fill water into the hoses - and the hydraulic excavator can start its work: the excavator arm and the shovel can be moved in three different directions. With mechanical chain drive and swivel excavator structure. With the Revell Engineers hydraulic excavator, children between 8 and 12 years old discover how the power of liquids can be used to perform mechanical work. With the step-by-step instructions (English language not guaranteed), boys and girls are accompanied to the functional model. The required tool is also included. This makes technology experienceable. This product promotes cognitive and motor skills: - Fine motor skills and handling tools - Concentration, patience and precise work - Spatial thinking (reading and understanding building instructions)