Q: What defines this Omega Seamaster Diver 300M Ref. 210.30.42.20.06.001?
A: It’s the modern 42mm Diver 300M in stainless steel with a blue unidirectional ceramic bezel and a grey ceramic dial in a PVD chrome colour, laser‑engraved with the signature wave pattern. It features a date at 6 o’clock, a screw‑down crown, the conical helium escape valve at 10 o’clock, a sapphire crystal with anti‑reflective treatment, and a transparent case back showing the movement.

Q: Which movement does it use and what performance can I expect?
A: The watch is powered by Omega’s Master Co‑Axial Calibre 8800, certified as a Master Chronometer. It offers a power reserve of approximately 55 hours, excellent anti‑magnetic resistance, and chronometer‑grade accuracy in multiple positions and temperatures.

Q: Is it suitable for swimming and diving?
A: Yes. The Diver 300M is rated to 300 metres and is purpose‑built for aquatic use. As with any pre‑owned watch, we recommend a current pressure test before prolonged immersion. Always ensure the crown is fully screwed down before contact with water.

Q: What does the helium escape valve do—and do I need it?
A: The manually operated valve allows trapped helium atoms to safely exit the case during professional saturation diving. Everyday users and recreational swimmers will not need to open it; keep it closed in normal use. Its conical design is engineered for added security in diving environments.

Q: Does it have sapphire crystals and an exhibition case back?
A: Yes. It features a scratch‑resistant sapphire crystal with anti‑reflective treatment and a sapphire display back so you can view the movement’s finishing.

Q: Does the bracelet have on‑the‑fly micro‑adjustment or a diver’s extension?
A: The stainless‑steel bracelet is fitted with a push‑button micro‑adjust clasp for quick, tool‑free sizing and includes a fold‑out diver’s extension for use over a wetsuit or for extra comfort in warmer weather.

Q: Will it fit my wrist and can you size it before shipping?
A: This piece is sized to fit up to approximately 20cm and comes with extra links (this set includes three). Share your wrist measurement and we’ll size the bracelet before dispatch; additional links can usually be sourced if required.

Q: What is included with this watch and how do you ensure authenticity?
A: It is a full set from circa 2020 and includes the original box, certificate/papers and three extra links. Every watch is inspected and authenticated by A Retro Tale and is supplied with our 12‑month mechanical warranty, insured shipping and a 14‑day return policy.

Q: Is any Omega factory warranty remaining on a circa‑2020 example?
A: Omega introduced a 5‑year international warranty for watches purchased on or after 1 July 2018. Whether coverage remains depends on the purchase date on the warranty card; many 2020 purchases would have matured by 2025. We can check the card and confirm for you.

Q: Can I see the Master Chronometer (METAS) test results for this watch?
A: If the Master Chronometer card is present, you can access the individual test results by scanning it with Omega’s app to view metrics such as daily precision and magnetic‑resistance performance.

Q: What is the lug width and can I use other straps?
A: The lug width is 20mm, so a wide range of 20mm straps will fit—rubber, NATO or leather—besides the supplied stainless‑steel bracelet.

Q: How should I wind and set the watch safely?
A: Unscrew the crown anti‑clockwise. In position 1 you can manually wind (about 20–30 turns if the watch is stopped). Pull to the next position to set the date, and to the final position to set the time. Avoid changing the date between roughly 8pm and 2am. Push the crown back in and screw it down firmly to maintain water resistance.

Q: How often should it be serviced?
A: For regular wear, a full service every 5–8 years is a sensible guideline. If you use the watch in water regularly, consider an annual or biannual pressure test to confirm water resistance, and service sooner if accuracy changes noticeably.