Omega Speedmaster Moonphase started from the mid to late 1980s (ref ST-345.0809) but only a handful of them were made. At around year 2000, Omega released an update version (with various subtle changes to the dial) ref 3876.5031. Various details were changed – ring around the register, steel bezel (old one has white gold bezel). Stainless Steel case 41mm, manual winding Cal.1866, 48 hours power reserve. Sapphire display caseback, moonphase accurate to 32months.