This vintage Rolex Bubble Back ref. 3131 is a rare and historically significant timepiece, crafted in 14kt yellow gold with a compact case measuring approximately 32 mm in diameter. It features a distinctive radium dial with warm, aged patina, complemented by applied hour markers and elegant hands, including a central seconds hand—a notable evolution for early Rolex models. Powered by a self-winding automatic movement, characteristic of the Bubble Back series, the watch is defined by its thicker, rounded caseback designed to house the rotor mechanism. This model perfectly embodies Rolex’s early innovation in waterproof automatic watches, offering timeless charm and strong collectible appeal.