The Rolex ref. 4663 comes from a totally different era than the Submariners and Daytonas we know today. Back then, Rolex was experimenting with style, elegance, and early automatic movements. The 4663 stands out immediately because of its square gold case. Instead of going with the usual round case, they went for a bold, almost architectural square shape. On the wrist, it’s understated and refined. Inside, it’s powered by one of Rolex’s early automatic movements, and the caseback bulges out a bit to make room for the rotor, which is why collectors call it a “Bubbleback.”