How does Hydraulic Robot Arm equate to fun? Children will have total command and visual manipulation using the science principles of a Hydraulic system and its application. Easy to follow instructions with detailed graphic illustrations pave the way for successful and satisfying kit building of 229 pieces. Compliment your engineering, math, science and technology learning strategy. No battery or motor required as it is powered by water, thus the 'Hydraulic significance and how it manipulates axes movement via lever controls. Suits ages 10 years and over.