The 6138 is one of several chrono calibers developed by Seiko in the 1970s. The 6138-300 was known as the "Jumbo" or "Big Chrono" due to its large multi-level dial. The lack of a wide bezel gives the watch a larger wrist presence than other 6138 models. The classic design is a bit more timeless than some of the other 1970s looks. Overall this watch is in (B) Very Good condition. The watch was serviced in October 2023 and the Chrono and quickset work as they should. The watch shows light scratches and scuffs on the case, crystal, and bezel. This watch oozes cool. It is fantastic on the wrist. 

- Ref No. : 6138-3000 "Jumbo"
- Serial No./Year: 277157/1972
- Case:
    42mm diameter, 19mm lug width, 15mm thickness
    Stainless Steel
- Crystal: Acrylic
- Movement & Accuracy: 
    Caliber: 6138 Automatic Chrono
    Complications: Chronograph, Day/Date
    Measured Accuracy: +9 sec/day.
    Amplitude: 220°
    Beat Rate: 21,600 A/h
- Band: Seiko 5 Sports Bracelet
- Condition Rank: (B): Very Good; Serviced October 2023
- Country of Manufacture: Japan

Condition Rank Guide:
-N: Item is in New Old Stock condition (NOS). Shows little to no signs of wear apart from some minor handling wear.
-A: Item is in Excellent condition. Micro-scratches can be seen on the sides of the case, bezel, and/or bracelet. No pitting/gouges on the case or scratches in the crystal.
-B: Item is in Very Good condition. Minor scratches and scuffs can be seen on the sides of the case, bezel, and/or bracelet. No pitting/gouges on the case or deep scratches on the crystal.
-C: Item is in Good condition. Moderate scratches and scuffs can be seen on the sides of the case, bezel, and/or bracelet. Minor pitting/gouges may be visible on the case. One or less deep scratches may be visible on the crystal. See photos.
-D: Item is in Fair condition. Heavy scratches and scuffs can be seen on sides of the case, bezel, and bracelet. Significant pitting or gouges are visible on the sides of the case and the crystal shows multiple deep scratches
-F: Item is in Poor condition. Item is not functional. For parts or repair only.