Roman Bronze Mask Puzzle Padlock; Roman Bronze Mask Puzzle Padlock, ca. 1st-3rd Century AD. A decorative and complex lock, this type of mechanical padlock "ring" would have been used to lock and secure a money pouch or small safe. When not in use as a security device, the lock simply appears to be a large ring. The hinged faceplate bears the image of a helmeted god. When this cover plate is lifted, a small keyhole is revealed on the inner plate. Inserting the key may not have been enough to release the shackle, however. Some locks had hidden tiny plates that needed to be engaged or switched before the ring would open. W. 1 1/8" H. 1 1/2", 1 5/8" deep..