Here is a very rare watch placed inside a hollowed out $20 U.S. gold coin. The movement is by Audemars Piguet. It is cal. 2003 hand wound chronometer grade. You may find other gold coin watches out there but in over 90% they contain a smaller 18K gold case which swivels out for winding or to gain access to the movement. I have looked extensively on the Internet and only found a very few with the same case construction as this one. They were made by Cartier.Notice that the dial is not signed, instead there is a AUDEMARS PIGUET on the bezel.