This is the bronze SD1971s which pays tribute to the Sumo Diver watch. There are a few theories as to how the Sumo got its name but one interesting one is that the marker at 12 looks like the "mawashi" worn by Japanese Sumo wrestlers during a match. This is a lovely looking watch with real presence and benefits from the following spec:
Movement: Japan NH35 automatic, 41 hours of energy storage.
Case material: Germany Cusn8 bronze
Case back: 316L stainless steel
Bezel: 120 click unidirect rotational bronze bezel
Watch mirror: sapphire crystal with AR coating.
Water resistance: 200 m / 20 ATM
Luminous: Swiss BGW9 blue super luminous.
Strap: Rubber with stainless steel clasp
Crown: Screwdown Crown
Case back: Screwback Case
Case diameter: 44.9mm ( without crown)
Case length: 52.5mm (lug to lug)
Case thickness: 14.7mm
Lug width: 20mm
Warranty: 2 years
Returns policy: 30-day return and refund.
Style: automatic watch, dive watch, luxury watch