This simplified model of an articulation or joint, will help teachers show kids (3-12) how muscles, bones, tendons hinged by articulations work. It is inspired by the elbow joint and it is meant to show how the arm moves.The model requires additional tubes, preferably cardboard, and some long balloons (the type to build balloon animals out of), and optionally tape and latex glove to make the hand. This makes it ideal for crafts project for kids to do. It is customizable so it fits all tubes...