The Seiko 6138 “UFO” is one of the brand’s most distinctive vintage chronographs — a bold, helmet-shaped case wrapped around Seiko’s legendary in-house automatic chronograph movement. Produced in the early to mid-1970s, the reference 6138-001X combines a bi-compax layout with an internal day–date display, wide baton hands, and a deep black dial with cream sub-registers that have aged attractively over time.
This example shows heavy patina across the tachymeter bezel and expected wear on the case and crystal, but the dial retains its depth and character. The 6138 movement is intact, and the watch comes fitted with its period-correct Seiko bracelet — a desirable detail for collectors. Despite the cosmetic wear, the watch remains an authentic and compelling slice of Seiko’s mechanical chronograph history.
A true collectible from the era that established Seiko as a serious chronograph manufacturer, prized for its bold case shape, dual-register layout, and robust mechanical engineering.
| Brand | Seiko |
| Reference | 6138-001X (“UFO”) |
| Movement | Seiko 6138 Automatic Chronograph |
| Case Material | Stainless Steel |
| Case Size | Approx. 44mm (excluding crown) |
| Dial | Black with cream sub-dials |
| Functions | Hours, Minutes, Seconds, Day, Date, Chronograph (Minutes + Hours) |
| Bezel | Tachymeter (worn/patinated) |
| Crystal | Acrylic |
| Bracelet | Stainless Steel Seiko Bracelet |
| Year | 1970s |
| Condition | Vintage – heavy patina on bezel; scratches on case and crystal; dial intact; movement present |