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Prospex Automatic Diver's Watch Re-Interpretation. Designed for those who treat life as the ultimate adventure, the Seiko Prospex line meets every challenge with technological excellence and style.

Based on an iconic Seiko design, with upgraded materials, this automatic diver's watch is crafted of stainless steel with durable super-hard coating, and offers a black uni-directional rotating elapsed timing bezel in scratch-resistant ceramic, a sapphire crystal with anti-reflective coating on the inner surface, a screwdown crown and caseback, and a tri-fold clasp with push-button release, secure lock and extender. The distinctive press-patterned gradated gray dial features a date calendar and LumiBrite hands and markers. Following ISO standards for scuba diving to depths of up to 200 meters, this exceptional timepiece includes a 24-jewel automatic movement with a frequency of 21,600 vibrations per hour, a power reserve of approximately 70 hours, and manual winding capability.


  • Product Number: 450018190680
  • Model Number: SPB323
  • Collection: Prospex
  • Movement: Automatic
  • Dial Colour/Material: Brown
  • Case Size: 45 mm
  • Case Material: Stainless Steel
  • Bracelet: Stainless Steel
  • Complication: Date
  • Warranty:

    3-year warranty
  • Case Thickness: 13.4 mm
  • Caseback: Plain, stainless steel
  • Bezel: Unidirectional rotating
  • Watch Crystal: Sapphire with anti-reflective coating on inner surface
  • Clasp: Three-fold clasp with Secure Lock & push button release, solid & slide adjuster
  • Power Reserve: 70 hours
  • Functions: Hours, minutes, seconds, date, stop seconds hand function
  • Water Resistance: 200 metres / 20 ATM
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EXTENDED HOLIDAY RETURN POLICY

For all regular-priced merchandise purchased online at MaisonBirks.com or in a Maison Birks or Birks Royalmount store from December 1st - 13th, 2025, returns and exchanges will be accepted until January 14th, 2026.

RETURNS

All watches purchased on MaisonBirks.com can only be returned or exchanged by mail within 30 days of delivery, provided merchandise has not been worn, altered, engraved, or special-ordered. All claims, returns, battery replacement, or warranty service must be accompanied by proof of purchase, original packaging and warranty materials. All returns are subject to a quality inspection to ensure the merchandise meets our return policy criteria. All merchandise purchased with cryptocurrency is final sale. For more information, click here.

Seiko

Seiko Prospex Sea Diver King Sumo Automatic 45 mm Stainless Steel

Prospex Sea Diver King Sumo Automatic 45 mm Stainless Steel
Estimated Price:
$ 1,550
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*This item is on order. This ring will be crafted just for you.
Contact an expert to confirm the delivery timeline.

All images shown are for illustration purposes only. Actual product may vary. Birks reserves the right to change the font, size and text orientation depending on the engraving message for best result.

Please note the estimated time for our engraving services is 7 to 10 business days. Engraved items are final sale.

Once adjusted Tudor watches are final sale.

Note that in store (after sale) adjustments to your Tudor watch is available exclusively in Official Tudor Maison Birks locations.

Prospex Automatic Diver's Watch Re-Interpretation. Designed for those who treat life as the ultimate adventure, the Seiko Prospex line meets every challenge with technological excellence and style.

Based on an iconic Seiko design, with upgraded materials, this automatic diver's watch is crafted of stainless steel with durable super-hard coating, and offers a black uni-directional rotating elapsed timing bezel in scratch-resistant ceramic, a sapphire crystal with anti-reflective coating on the inner surface, a screwdown crown and caseback, and a tri-fold clasp with push-button release, secure lock and extender. The distinctive press-patterned gradated gray dial features a date calendar and LumiBrite hands and markers. Following ISO standards for scuba diving to depths of up to 200 meters, this exceptional timepiece includes a 24-jewel automatic movement with a frequency of 21,600 vibrations per hour, a power reserve of approximately 70 hours, and manual winding capability.


  • Product Number: 450018190680
  • Model Number: SPB323
  • Collection: Prospex
  • Movement: Automatic
  • Dial Colour/Material: Brown
  • Case Size: 45 mm
  • Case Material: Stainless Steel
  • Bracelet: Stainless Steel
  • Complication: Date
  • Warranty:

    3-year warranty
  • Case Thickness: 13.4 mm
  • Caseback: Plain, stainless steel
  • Bezel: Unidirectional rotating
  • Watch Crystal: Sapphire with anti-reflective coating on inner surface
  • Clasp: Three-fold clasp with Secure Lock & push button release, solid & slide adjuster
  • Power Reserve: 70 hours
  • Functions: Hours, minutes, seconds, date, stop seconds hand function
  • Water Resistance: 200 metres / 20 ATM
View More Details
View Fewer Details

EXTENDED HOLIDAY RETURN POLICY

For all regular-priced merchandise purchased online at MaisonBirks.com or in a Maison Birks or Birks Royalmount store from December 1st - 13th, 2025, returns and exchanges will be accepted until January 14th, 2026.

RETURNS

All watches purchased on MaisonBirks.com can only be returned or exchanged by mail within 30 days of delivery, provided merchandise has not been worn, altered, engraved, or special-ordered. All claims, returns, battery replacement, or warranty service must be accompanied by proof of purchase, original packaging and warranty materials. All returns are subject to a quality inspection to ensure the merchandise meets our return policy criteria. All merchandise purchased with cryptocurrency is final sale. For more information, click here.

Prospex Automatic Diver's Watch Re-Interpretation. Designed for those who treat life as the ultimate adventure, the Seiko Prospex line meets every challenge with technological excellence and style.

Based on an iconic Seiko design, with upgraded materials, this automatic diver's watch is crafted of stainless steel with durable super-hard coating, and offers a black uni-directional rotating elapsed timing bezel in scratch-resistant ceramic, a sapphire crystal with anti-reflective coating on the inner surface, a screwdown crown and caseback, and a tri-fold clasp with push-button release, secure lock and extender. The distinctive press-patterned gradated gray dial features a date calendar and LumiBrite hands and markers. Following ISO standards for scuba diving to depths of up to 200 meters, this exceptional timepiece includes a 24-jewel automatic movement with a frequency of 21,600 vibrations per hour, a power reserve of approximately 70 hours, and manual winding capability.


  • Product Number: 450018190680
  • Model Number: SPB323
  • Collection: Prospex
  • Movement: Automatic
  • Dial Colour/Material: Brown
  • Case Size: 45 mm
  • Case Material: Stainless Steel
  • Bracelet: Stainless Steel
  • Complication: Date
  • Warranty:

    3-year warranty
  • Case Thickness: 13.4 mm
  • Caseback: Plain, stainless steel
  • Bezel: Unidirectional rotating
  • Watch Crystal: Sapphire with anti-reflective coating on inner surface
  • Clasp: Three-fold clasp with Secure Lock & push button release, solid & slide adjuster
  • Power Reserve: 70 hours
  • Functions: Hours, minutes, seconds, date, stop seconds hand function
  • Water Resistance: 200 metres / 20 ATM
View More Details
View Fewer Details

EXTENDED HOLIDAY RETURN POLICY

For all regular-priced merchandise purchased online at MaisonBirks.com or in a Maison Birks or Birks Royalmount store from December 1st - 13th, 2025, returns and exchanges will be accepted until January 14th, 2026.

RETURNS

All watches purchased on MaisonBirks.com can only be returned or exchanged by mail within 30 days of delivery, provided merchandise has not been worn, altered, engraved, or special-ordered. All claims, returns, battery replacement, or warranty service must be accompanied by proof of purchase, original packaging and warranty materials. All returns are subject to a quality inspection to ensure the merchandise meets our return policy criteria. All merchandise purchased with cryptocurrency is final sale. For more information, click here.

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