Overview

The Seiko Prospex “Sumo” is one of the brand’s most beloved modern divers — big, bold, and built for decades of service. This SPB103J1 variant adds a deep emerald-green dial and matching bezel, balancing rugged tool-watch attitude with a refined burst of color. At 45 mm it wears with presence but remains comfortable thanks to its curved lugs and balanced weight.

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• Reference: SPB103J1 (“Green Sumo”)

• Case Size: 45 mm stainless steel (52.5 mm lug-to-lug)

• Dial: Sunburst green with applied indices and Lumibrite hands

• Bezel: Unidirectional green insert with 120 clicks

• Movement: Seiko Caliber 6R35 (automatic, 70-hour power reserve)

• Crystal: Sapphire with anti-reflective coating

• Bracelet: Stainless steel with folding clasp and diver’s extension

• Water Resistance: 200 m (ISO certified)

• Inclusions: Full kit – box, papers, warranty card

• Condition: Very nice pre-owned; light surface wear on clasp only

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Case #131 emerges as a prime example of Seiko’s tool-watch craft. Nicknamed for its broad, muscular casing, the “Sumo” has earned cult status among diver fans for its balance of value and performance. The green SPB103J1 offers a refreshing twist on the classic blue and black variants — its dial shifts from olive to emerald as light moves across it, giving it unexpected depth. Backed by the 6R35 movement and Seiko’s unmatched reliability, this is an everyday diver that punches well above its price.

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Favored by enthusiasts who value honest engineering and under-the-radar credibility — a true deal-hound favorite in full kit form.