Bardzo ciekawy model - King Seiko 5246-6000 Chronometer Special, Hi-Beat, mechanizm który spokojnie dotrzymuje kroku nawet dzisiejszym chronometrom i dał bazę do Grand seiko 4S. Jak na 46-latka bardzo dobry stan zachowania, piękna "lniana" tarcza, stojące logo "SEIKO" i "KS" - GSy miewają gorsze I trochę informacji historycznych z netu: "I strongly believe that 52 King Seiko special chronometer quality exceeded Grand Seikos.The brand name "King Seiko" was the symbol of Daini-Seikosha. In the '70 era, the quartz watch sale became very rampant. At that stage, Daini Seikosha thought that the 52 caliber was the last chance to produce for mechanical watches, and thus, they felt that they should produce a superior caliber to remain part of the watch history. - Durability - Thin caliber - The function with day and date change quickly at 24:00 - One piece case for perfect water proof (Honestly speaking the water proof ability was a weakness. Almost people take a bath and swim with the watch. So it is hard to find no stain dial on the 52 King Seiko special.) The 8 bps movement was more durable than the 10 bps movement. This could be due to that 10 bps 45 caliber needed more frequent maintanence.. Thus, Daini-Seikosha produced the new caliber based on the experience. 52 caliber!! Based on selection of only high precision parts, 52 King Seiko Special chronometer was born!! This caliber design was so great that it was modified to become the famous 4S caliber after about 20 years. Because of this superb caliber, Daini-Seikosha named it "Special " (as to more superior) than normal King Seiko . Lastly, I think 52 King Seiko quality exceeded those of the Grand Seikos." Seyia Kobayashi Of the Seiko vintage high-grades, the 52 Series was the only one that did not equip a Grand Seiko, i.e. “GS52” was never made. This was likely because Daini Seikosha, who produced the 52, wanted to the range-topping 52xx to be a Certified Chronometer. This does not mean that the 52 was not developed to Grand Seiko Standards (“AA” Accuracy of -3/+5 sec per day). On the contrary, there exists a "Grand Seiko 52", except it wasn't released as such, but as the 52 KING SEIKO Special Chronometer (5246-6000). The 52KS "Special" Chronometer in the monocoque -6000 case is not to be confused with lesser 52KS Chronometers that are more common. The latter are KS (“A” Accuracy Standard) that have been adjusted to chronometer specs and certified as such, while the "KS Special" denotes an AA Accuracy Standard, aka GS Standard, of -3/+5 sec per day. A respected Seiko collector in Japan, Seiya Kobayashi, detailed the history of GS with a postscript stating that he “strongly believes that the 52 King Seiko Chronometer’s quality exceeds that of the Grand Seiko". This has been well-documented and referenced throughout the SEIKO collectors’ communities worldwide.What gives the 52 Stream monumental significance in SEIKO’s history is the fact that, in the late 90s, the Japanese Manufacture resurrected the 52 and re-designated it the 4S Series. Today, the SEIKO 4S series of high-grade mechanical movements equip luxury-range SEIKO Brightz (4S27, 4S29) and high-end SEIKO Credor (4S76, 4S77). Despite the supreme quality of the 4S Series, no current 4S matches the performance and precision of the 52 KS Special Chronometer 5246. While the range-topping 4S76 and 4S77 are adjusted to -10/+15 sec per day, the KS Special Chronometer was tuned to Grand Seiko accuracy grade of -3/+5 sec per day. While those unfamiliar with SEIKO would marvel at the "Chronometer" in the name, SEIKO purists know that it is the “KS Special” (AA Accuracy) designation that exceeds its Chronometer certification.Within the 52 KS Special Chronometer, SEIKO was able to produce a Grand Seiko and an Officially Certified Chronometer at the same time. All was encased in a beautifully sculptured case with SEIKO’s signature reverse curves, still found on their high-end offerings today. https://www.timekeeper.co.nz/viewtopic.php?t=5553