This 4823-8120, unlike its close relative the 8050, came with a bracelet originally. It is a very solidly made quartz (your watchmaker will love it!), much thicker than its descendant the 5856. To be sure, it has huge presence and its thermo-compensation, due to its relative thickness, is still excellent after all these years.
The dial work is impeccable, this truly is a high end watch. You noticed of course the black tip hands? It gives this watch something extra..... great legibility and some "punch". That punch is also implemented in the mechanics of this watch, it has that special Seiko gimmick of the "jumping seconds hand". This means that it will jump ahead 10 seconds when you pull the crown to adjust the time. It makes time setting so much easier!
In my experience these single quartzes are among the most accurate vintages; the twin quartzes like the 99 series have the specs for sure, but after 40 years or so… build quality and robustness gain the upper hand. The early King Quartzes truly shine!
The King Quartz at hand is fully original with bracelet and runs to specs.

Manufacture: Seiko
Model:            King Quartz
Reference:     4823 8120
Movement:     Quartz at 10 Seconds PY
Serial No.:      70xxxx
Case:              Tanaka design 36x42x11mm without crown
Crystal:           Acrylic 30mm, Serial#: 300WA4GA00
Dial:                Silver Snow
Bracelet:        XBB090  190 mm around, bracelet links: split pin
Lugs & Clasp: 18mm lugs, springbar diameter: 1,8x17mm, clasp diameter: 17mm clasp, clasp pin: 1,0x16mm
Production:   1977-10
Condition:       07 - Good: very clean, some light scratches case & crystal, easily polished
Service:           Not necessary
Box:                 No
Papers:           No