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SEIKO PROSPEX – Pro Marine Master 300m SLA023J1


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Seiko Prospex Pro Marine Master 300m Automatic Men’s Stainless Steel Bracelet Watch

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Included with product:
* Branded Packaging
* Completed Warranty
* Free Bracelet Sizing
* Free Gift Wrapping

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First produced in 1968, the stunning Seiko Marine Master has been re-imagined for today. Modelled on the original Marine Master MM300, the modern Seiko Prospex Pro Marine Master is certain to impress.

Water resistant to 300 m/1000 ft the Marine Master is built for saturation diving. Made for professional divers, it is deliberately uncomplicated. This allows the quality of the movement and the ergonomic case and bracelet to shine through.  With a one piece structure, the heavy-duty brushed stainless steel case is 44.3mm in diameter. The deep blue dial has high-visibility hour markers and hands coated in Lumibrite. A legible minute track is also at the extreme edge. Surrounding the dial, there is a blue ceramic uni-directional turning bezel in dark blue.

Equipped with an automatic 8L35 calibre movement, the Seiko Prospex Pro Marine Master is accurate to +15 to -10 seconds per day with a power reserve of approximately 50 hours. Presented in a box with an additional silicone strap, this is a first-rate professional divers watch. For complete peace of mind, it is covered by a two year manufacturer’s warranty.

  • Automatic movement calibre 8L35 with manual winding capacity
  • 26 jewels
  • Accurate to +15 to -10 seconds per day
  • Duration: approx. 50 hours
  • Stainless steel case, one piece structure, ceramic unidirectional turning bezel
  • Case dimensions: 44.3mm diameter, 15.4mm deep
  • Date display
  • Stop second hand function
  • Blue dial – indexes and hands with Lumibrite
  • Stainless steel bracelet, three-fold clasp with secure lock, push button release, solid & slide adjuster
  • Additional silicone strap included
  • Sapphire crystal – anti-reflective coating on inner surface
  • Screw-down crown
  • Water resistant 30 bar (300m)/1000ft – for saturation diving
  • Two Year Manufacturer’s Warranty
Additional information

Seiko Prospex



Movement Type

Automatic Mechanical

Case Shape


Dial Colour


Material Type

Stainless Steel

Strap Type

Metal Bracelet

Water Resistance


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  1. PB

    From a easy to use website, a great customer service and fast delivery I thought Watch Specialist provided a great service. Even when I phoned with a query Suzie was very helpful, she dealt with my concerns in a professional but friendly way. My beautiful watch arrive two days after I order it.

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    Easy to order, quick delivery and good customer service

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    fast delivery, great prices, good and easy website

  4. AB

    Il sito è molto fruibile e gli articoli almeno nel mio caso sono ben descritti, il servizio clienti è ben disponibile e la consegna abbastanza veloce.

  5. A

    First Class. Great communication and speedy delivery.

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