3-in-1 Hydraulic Robot Arm 🌠 ⚡️Discover and apply hydraulic power with this multi-axis robotic arm. ⚡️Water is all that's needed to make it move. Includes all parts needed to make the Mega Hydraulic Arm Robot and detailed instructions. ⚡️A fun and impressive science kit. ⚡️You don't need a battery, you don't need a motor, just water can drive your mechanical arm. The pressure of the water is converted into power, so that the operating lever can easily control various joint activities of the mec