Black Friday · Through November 30

Extra 10% off all watches

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Code WATCH10

Online only, through November 30, 2026 at 11:59 pm PT. One discount code per watch.

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Seiko - Brand New

Seiko Prospex "Sumo" - SPB101

  • 45.0 mm case
  • Sapphire crystal
Sale price $680.00
Regular price $850.00
Sold out

About this timepiece

Substantial and serious about the sea, the Seiko Prospex Sea Automatic Diver (ref. SPB101) pairs a black dial with a black unidirectional rotating bezel in a bold 45mm stainless steel case. LumiBrite on the hands, indexes and bezel glows clearly when the light drops, with a date window for day-to-day convenience. The black-on-black dial and bezel keep the look clean and versatile, as easy to wear with a wetsuit as with a blazer.

Seiko's caliber 6R35 automatic movement supplies approximately 70 hours of power reserve with 24 jewels, and it can be wound by hand whenever needed. A sapphire crystal protects the dial, while a screw-down crown and screw case back deliver 200 meters of diver's water resistance. The stainless steel bracelet closes with a three-fold clasp that adds a secure lock, push-button release and extender, completing a diver's watch of real substance at 188 grams.

Features

  • Caliber 6R35 automatic – 24 jewels and approximately 70 hours of power reserve, with manual winding.
  • 200m diver's water resistance – secured by a screw-down crown and screw case back.
  • Black unidirectional bezel – a rotating bezel with LumiBrite, matched to the black dial.
  • Sapphire crystal – protects the dial of the 45mm stainless steel case.
  • Secure three-fold clasp – stainless steel bracelet with secure lock, push-button release and extender.

Specifications

  • Reference: SPB101
  • Collection: Prospex Sea
  • Gender: Men's
  • Caliber Number: 6R35
  • Movement Type: Automatic with manual winding
  • Precision: +25 to -15 seconds per day
  • Power Reserve: Approx. 70 hours
  • Jewels: 24
  • Functions: Stop second hand function, date display
  • Case Material: Stainless steel
  • Diameter: 45.0 mm
  • Thickness: 12.9 mm
  • Lug-to-Lug: 52.6 mm
  • Dial Color: Black
  • Crystal: Sapphire crystal
  • LumiBrite: LumiBrite on hands, index(es) and bezel
  • Band: Stainless steel bracelet
  • Clasp: Three-fold clasp with secure lock, push button release with extender
  • Distance Between Lugs: 20 mm
  • Water Resistance: 200m / 660ft diver's
  • Weight: 188.0 g
  • Features: Unidirectional rotating bezel, screw-down crown, screw case back

Timepiece History

Seiko's story began in 1881, when a 21-year-old entrepreneur, Kintaro Hattori, opened a shop selling and repairing watches and clocks in central Tokyo. The first watch to carry the Seiko name followed in 1924, and Seiko went on to introduce a long line of watchmaking firsts, including the Quartz Astron, the world's first quartz wristwatch, on December 25, 1969. In 2024, Seiko celebrated the 100th anniversary of the Seiko brand.

The SPB101 belongs to the Prospex Sea line, a diver's watch lineage that traces back to 1965, when Seiko introduced Japan's first diver's watch, a self-winding model water resistant to 150 meters that was used on the 8th Japanese Antarctic Research Expedition in 1966. In 1975, Seiko's Professional Diver's 600M became the world's first diver's watch with a titanium case, and Seiko has continued to engineer its divers around the demands of real underwater conditions.

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Lease-to-own · Acima or Progressive No credit needed* · 90-day purchase option

Lease-to-own is not a loan or credit, so there's no APR. Your payment amount and schedule are set in your lease agreement and depend on your state and pay schedule. The lowest-cost way to own is the 90-day purchase option.

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  • Approvals up to $5,000
  • 90-day early purchase option (3 months in CA)
  • Own in 12, 18 or 24 months
  • Payments set around your payday
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  • No credit needed*
  • 90-day purchase option (3 months in CA)
  • 12 months to ownership
  • Weekly, bi-weekly or monthly payments
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