Years: ~1957–1989 (longest‑running reference)

Case: 34 mm Oystersteel, acrylic crystal, Oyster bracelet, drilled then later solid lugs, 100 m WR

Movements:

• Cal. 1520 (“PRECISION”) or Cal. 1530 (“SUPER PRECISION”)—varying due to jewel-count import laws
• Typical beat rates: ~19,800 vph (1520) or 18,000 vph (1530); accuracy within standard non‑COSC ±10‑15 s/day

Dial Variants: Stick indices, occasional 3–6–9 Explorer style, black/grey/salmon dials, corporate logos (e.g. Domino’s Pizza)

Notes on variants:

5520: gold‑filled cap model

5504: 35 mm two-tone or Explorer‑style dial

5501, 5502, 5506: gold-plated or Rolesor export models

5700 / 5701: Air‑King Date versions with Cyclops and acrylic crystal