The Omega Speedmaster Speedy Tuesday Limited Edition is kind of made by Speedmaster fans for Speedmaster fans
Omega caliber 1861 (base Lemania caliber 1873) | Hand-wound | Diameter: 27 mm (12 lignes) | Thickness: 6.87 mm | Frequency: 21,600 vph (3 Hz) | Jewels: 18 | Hours, minutes, small seconds, chronograph | Power reserve: 48 hours
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This movement is an improvement of the original Speedmaster caliber 321 from 1949 that served in the first Speedmasters. In 1968 this caliber 321 was replaced by the Omega caliber 861, that was in production until 1997. Then it was replaced by the caliber 1861 with rhodium plated finish. and is basically found in Omega Speedmaster Professional Moonwatch models, from 1996 and onwards.
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A variant of this movement is the Omega caliber 1863, which is almost the same however it has a more luxurious finish. So, the 1863 is more used in Speedmasters with a transparent case back. The Omega 1861 has an accuracy of -1 to +11 seconds per day.
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In 2019 Omega launched a successor, the Omega caliber 3861.
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Watches with the Omega caliber 1861
This new Omega Speedmaster CK 2998 Limited Edition is in fact an updated version with the classic model from 1959 as inspiration