What the number 220.12.41.21 covers
220.12.41.21 is the opening block of an Omega Seamaster Aqua Terra reference. Omega splits every reference into blocks. 220 marks the Aqua Terra 150M family. 41 is the case diameter in millimeters. 21 covers the movement class, an automatic with a date. The last three digits set dial color and strap or bracelet. Full genuine references in this block include 220.12.41.21.01.001 with a black dial and 220.12.41.21.03.001 with a blue dial.
The genuine watch is the Aqua Terra 150M Master Chronometer 41 mm. It carries a steel case, a domed sapphire crystal with anti-reflective coating on both faces, and a sapphire caseback. Water resistance is 150 m. The dial has the teak pattern, horizontal lines cut across the face, and a date window at 6 o'clock.
Genuine specs that replicas copy
- Movement: Omega Co-Axial Master Chronometer Calibre 8900, automatic, twin barrels, 60 hour power reserve.
- Rate: 25,200 vibrations per hour, 3.5 hertz. 39 jewels.
- Magnetic resistance: 15,000 gauss. METAS certifies each movement through eight tests.
- Case: 41 mm wide, 13.2 mm thick, 20 mm lug width.
- Crystal: sapphire front and back.
- Bracelet: steel, butterfly clasp with push buttons.
What a replica 220.12.41.21 holds inside
No replica runs a Calibre 8900. The common substitute is a modified ETA 2824 pattern or a Chinese automatic such as a Hangzhou or Seagull build. Most of those beat at 28,800 vibrations per hour, a rate the genuine calibre does not use. Power reserve lands at 38 to 42 hours, not 60.
Case steel is 316L in most builds. Genuine Omega also uses 316L on this model, so hardness is close. Case thickness on replicas sits at 13.5 mm to 14.5 mm, against 13.2 mm on the genuine watch. Weight on a full bracelet runs about 150 g to 180 g.
None of these watches hold METAS certification. None resist 15,000 gauss. Sellers state 150 m water resistance, but most builds are not pressure tested to that figure. Gaskets are the weak point on every tier.
Details that mark a good build from a poor one
- Dial texture. The teak lines should be sharp and spaced at equal gaps. Blurred lines or flat printing mark a low tier.
- Date font. Numeral shape is a known tell. Compare the 1 and the 4 against a photo of the genuine dial.
- Hands. The arrow hand has a defined point. Rounded or thick tips are wrong.
- Crystal height. The domed sapphire should sit close to the bezel, not above it.
- Clasp. The butterfly clasp should close flush. A 1 mm gap shows on the wrist.
- Lume. Pigment color should match the genuine dial under a dark room test.
Price, service, and legal facts
Replica prices for this model run about 300 to 600 US dollars. Movement service costs 150 to 300 dollars at an independent watchmaker. Omega will not service a counterfeit and will not sell parts for one. Resale value is near zero.
In the United States, trafficking in counterfeit goods is a federal crime under 18 U.S.C. 2320. Customs officers can seize shipments. Penalties reach 10 years in some first offense cases.