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  13 May 2014 Last updated at 13:00 BST
  The mechanical hands have joints and fingers like real hands.
  They are very sensitive and can be used to pick up delicate objects like eggs.
  The new arms make it easier for people who have lost a limb to care for themselves and do everyday tasks like doing up zips.
summary: New high tech robotic arms which can be used for delicate tasks have been approved for use by people in America.