Vintage Seiko Presmatic watch. Reference 5146-7090. This watch was produced by Dani-Seikosha in 1970. Dani-Seikosha was responsible for producing the entirety of the King Seiko lineup (except 56KS). The Presmatic was one of their incredible design innovations. Named after its unique date quickset mechanism, the Presmatic is an important piece of Seiko history. It features a beautiful linen dial, quickset, quickchange day and date indicators, and a hi-beat automatic movement. 

A note on the Presmatic Quickset System: The day can be advanced by utilizing the time setting function of the watch. Advancing the time to 12-1 AM will cause the day to change over, moving the hands counter clockwise (back) to about the 9PM position will allow the date gear to reset, you can then again advance the time to 12-1 AM, the day will advance once more. This process can be repeated until the desired day is reached. Then, you can set the time normally using the crown. Once the time is set, the date can be set by pressing the button located on the inside of the crown until the correct date is indicated. WARNING: Do not use the quickset button while the watch is between 9PM and 3AM. Doing so could cause damage to the quickset mechanism. 

- Ref No. : 5146-/-7090
- Serial No./Year: 052798-/-1970
- Case:
    37mm diameter, 18mm lug width, 10mm thickness, 29.75mm Lug-to-lug.
    Stainless Steel
- Crystal: Plexiglass/Acrylic
- Movement & Accuracy: 
    Caliber: Dani-Seiko Cal. 5146
    Complications: Quickset Day/Date Indicators (Fully Functional)
    Measured Accuracy: -17 sec/day.
    Amplitude: 170°
    Beat Rate: 28,800 A/h
- Band: Replacement Bracelet. Will Fit Wrists ~ 7.5"
- Condition Rank: (C) Good Condition. Please See Photos and Condition Rank Guide
- 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.