<mujoco model="square_peg">
  <worldbody>
    <body name="square_peg" pos="0. 0. 0." >
        <geom pos="0.5 0.2 0.08" size="0.016 0.016 0.1" type="box" rgba="0 0 1 1"/>
    </body>
  </worldbody>
</mujoco>