Explore the fascinating world of hydraulics and robotics with the Little Story DIY Hydraulic Power Principle based 3-in-1 Mechanical/Robotic Arm Toy by SAMBOX. Designed for kids aged 8 and above, this 220-piece STEM kit teaches principles of hydraulic power through hands-on assembly without the need for batteries or motors. Using water to drive the mechanical arm, kids can control movements with an operating lever and freely switch between three functional heads - grasper, grabber, and suction cup. The robotic arm features 270° rotation at the base for versatile play and encourages imagination, creativity, and problem-solving. Made from durable, eco-friendly ABS plastic and EN71 certified for safety, this educational toy enhances STEM skills while providing hours of fun. Perfect as a birthday, holiday, or special occasion gift. diy hydraulic robotic arm mechanical arm toy stem educational kit 3-in-1 hydraulic power kids science technology engineering math grey en71 certified birthday gift