A farmer from Germany has become the first person ever to have a double arm transplant.
Karl Merk lost his arms in a farm accident six years ago, but in July, doctors did a 15-hour operation to fix the donor arms to his body.
Mr Merk, who's 54, can already do simple things like open doors and turn lights on and off.
But doctors say it could take up to two years before he re-learns how to use his hands.
It took five teams of medical professionals, including surgeons, nurses, and other helpers, to carry out the operation.
Mr Merk said when he first woke up, he could not believe it had worked.
He said it felt "overwhelming" to have two arms again.