Omega Ref. 2998-4

OMEGA FIRST-GENERATION SECOND VERSION PRE-MOON & PRE-PROFESSIONAL SPEEDMASTER CHOCOLATE DIAL STEEL Omega, "Speedmaster", movement No. 19584900, Ref. 2998-4. Made in 1962. Very fine and very rare, water-resistant, stainless steel wristwatch with black to brown color-change dial, round button chronograph, 12-hour and 30-minute registers and tachometer bezel. Three-body, polished and brushed, color-change black to gray bezel with tachometer scale to 500 UPH, concave lugs, screw-down case back with Speedmaster logo, dust cap. Brown with luminous baton indexes, outer minute/ seconds divisions, outermost 1/5th second divisions, subsidiary dials for the seconds, the 12-hour and 30-minute registers. Luminous steel alpha hands. Cal. 321, copper-colored, 17 jewels, straight-line lever escapement, monometallic balance, shock absorber, self-compensating Breguet balance spring, index regulator. Notes Dial, case and movement signed. DIAM. 39.5 mm. THICKNESS 13.5 mm. The dial of this watch is known as a "Chocolate Dial" due to the even change of color from black to chocolate brown. Consigned from a private owner, the present watch is an excellent and original example of a first-series Speedmaster. This model is the second version of the first-series, only differing by the alpha hands and black aluminium tachometer ring instead of arrow hands and engraved tachometer on the first model. The caliber 321 was used in the Speedmaster until 1968 when it was succeeded by the caliber 861.