Highly unusual and impossibly rare large model Cartier tank American watch with diamond set case, winding crown and mechanical hand wound movement. This collectible watch would have a huge retail value at Cartier. Immaculate 'original' condition. 18ct white gold case and bracelet. This is the very first watch of its type we have seen and we are confident that these watches with the 'non-auto' movements were not produced in large numbers at all.