Short answer
The 220.12.41.21 code covers the 41mm Omega Seamaster Aqua Terra 150M Master Chronometer with a teak pattern dial. Replica builds of this model sell between $120 and $450. The price tracks three things: the movement, the dial print, and the bracelet. No replica carries METAS Master Chronometer certification. Before paying, compare the date window, the dial grooves, and the crown.
What the reference number means
Omega builds the code from blocks. 220 marks the Seamaster Aqua Terra 150M line. 12 marks a steel case on a steel bracelet. 41 is the case diameter in millimeters. 21 is the caliber family. The last digits mark the dial. 220.12.41.21.03.001 has a blue dial. 220.12.41.21.01.001 has a black dial. 220.12.41.21.02.001 has a silver dial.
Genuine specs to compare against
- Case: 41mm steel, 13.2mm thick, 20mm lug width
- Water resistance: 150m
- Calibre 8900, twin barrel, 60 hours power reserve
- Magnetic resistance to 15,000 gauss
- Sapphire crystal front and back
- Date window at 6 o'clock
- Co-axial escapement
Replica movement options
Three movement types show up in this case. Entry builds use a DG2813 or a Miyota 8215, both at 21,600 vph. Mid tier builds use an ETA 2824 clone at 28,800 vph. Top tier builds use a decorated 2824 with a rotor stamped 8900. None of these are co-axial. None hold a METAS certificate. The seconds hand sweep reads smoother on the 28,800 vph versions because they beat eight times per second. The 21,600 vph versions beat six times per second.
Dial and case details that separate builds
- The teak lines. Genuine dials have horizontal grooves with even spacing and sharp edges. Cheap copies show soft ridges and shallow depth.
- The date window. It sits at 6 o'clock inside a chamfered frame.
- The applied logo and the Omega text under 12. Genuine print stays crisp under 10x magnification.
- The caseback. Genuine uses a sapphire display back with a NAIAD lock ring. Some replicas use mineral glass. Others use solid steel.
- The crown. Genuine uses a conical crown with the Omega symbol. Copies often show a soft logo.
Water resistance
Sellers claim 30m to 50m on tested replica cases. No public test data backs that claim. Gaskets on entry cases sit loose. Do not swim with a replica unless a watchmaker pressure tests it and replaces the gaskets. The genuine rating is 150m.
Size and fit
The case is 41mm wide, 13.2mm thick, with 20mm lugs. Lug to lug is about 48mm, so it fits wrists from roughly 16cm to 20cm. Bracelets on most replicas use screw links or pin and collar links. Screw links are simpler to size at home.
Price bands
Entry: $100 to $180. Mid tier: $200 to $300. Top tier: $320 to $450. Top tier orders often ship with a box, papers, and a hang tag. Those items do not change the watch.
What is unknown
Factory names change. Stock moves between sellers. No public database tracks the serial numbers of the genuine run for 220.12.41.21.03.001, so a serial lookup cannot confirm a replica or a genuine watch.