In 1975, Seiko released the two lines that would continue their dominance in the Quartz Revolution for a decade until 1985, when these two product lines were retired. The King and Grand Quartz models from Seiko boasted extreme accuracy which was unheard of at the time of their release. The lowest end model, being the 48KQ, was rated to 10-15 seconds per month. While the highest Twin-Quartz crystal 97KQ and 99KQ models were rated to 20 seconds per year! 

The Grand Quartz line was similar to the King Quartz, but boasted even higher accuracy ratings and finishing quality. Their lowest end model running similarly to the KQ, the 48GQ was rated to 10-15 seconds per month, while the high end, twin-quartz model, the 99GQ was rated to just 10 seconds per year. For comparison, the current Grand Seiko 9F quartz movements are rated at 10 seconds per year.  

This particular watch is the Twin King Quartz 99KQ. Reference Number 9923-7020. This watch gets its name from the two quartz crystals in the movement. One is used for standard timekeeping, while the other is used for temperature measurement and regulation. Overall this watch is in (B) Very Good Condition. Minor scratches and scuffs can be seen on the case, bezel, and bracelet. There is moderate plating wear on the case and bezel.

New silver oxide battery installed. Includes a 1 year battery replacement warranty. Should the battery die within 1 year of purchase, GC Murphy will replace the battery for free. Warranty registration required.

Ref No. : King Twin Quartz 9923-7020
- Serial No./Year: 960710-/-1979 or 1989
- Case:
    35mm diameter, 18mm lug width, 8.6mm thickness, 41.15mm Lug-to-lug.
    Gold Plated Stainless Steel
- Crystal: Hardlex
- Movement & Accuracy: 
    Caliber: Suwa-Seikosha Cal. 9923 Quartz
    Complications: Temperature Compensation, Quickset Day, Date Indicators
    Stated Accuracy: 20 sec/year.
    Stated Power Reserve: 3 Year
- Band: Replacement GP Bracelet
- Condition Rank: B, Very Good Condition. Please See photos.
- 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.