Description: Rolex Oyster Precision 6426 Pre-owned Rolex Oyster Precision ref. 6426 (1981) is a bit of an oddity among Rolex’s offerings because it relies on hand-wound technology rather than automatic, aka “Perpetual.” As a result, the dial is still marked “Oyster” for the waterproof Oyster case but features the distinction “Precision” instead of “Perpetual”. Aside from this small detail, it’s every bit the classic vintage Rolex dress watch.