Plastic Material: Hydraulic Robot Arm Kit Is Made Of High Quality Plastic Material, Safe And Eco Friendly, Firm And Sturdy, Stable And Wear Resistant, Durable. Reasonable Structure And Design: The Arm Can Be Rotated 270 Degrees From The Base. Kids Can Easily Switch Between Grab Or Suction Cups Depending On What They Are Moving. Hydraulic Power: No Need Batteries And Motors, Water Can Drive The Mechanical Arm, The Principle Of Hydraulic Power, Use Operating Lever To Control Various Joint Activities Of Mechanical Arm. 3 In 1 Hydraulic Robot Arm: Clamp, Suction Cup And Hydraulic Grab, Give Full Play To Your Imagination, Feel The Fun Brought By The Hydraulic Mechanical Arm. Diy Assembly Toy: Mechanical Arm Is Constructed By A Variety Of Components, Kids Need To Assemble Them Together, Develop Hands On And Thinking Skills.