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Seiko Prospex ‘Sumo’ Automatic Green Dial Stainless Steel Bracelet Mens Watch SPB103J1

Product Code: SPB103J1 Categories: , , ,


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Seiko Prospex ‘Sumo’ Automatic Green Dial Stainless Steel Bracelet Mens Watch SPB103J1 

The Case:

The Seiko Prospex ‘Sumo’ SPB0103J1 case is made from 316L stainless steel and it has been hardened in Seiko’s scratch-resistant DiaShield coating.  It measures 44mm in diameter, which places this watch in the midsize range, allowing it to sit comfortably on a range of wrists. The watch’s curved lugs also allow it to hug the contours of the wearer’s wrist. The screw-down crown is located at 4 o’clock, which is feature common amongst many of Seiko’s most iconic diver watches, because it permits great comfort when on the wrist and also additional practicality when it comes to preventing it getting knocked out of place.

A 120-click unidirectional stainless steel bezel sits proudly on top of the case. The bezel displays a 60-minute scale with a luminescent pip present at the 12 o’clock marker, the bezel has been highly polished which bestows it with a glossy appearance. Similarly, the easy-to-grip coin-style bezel has also been treated to the same polished finish. On the back of the case there is a screw in solid case back which ensures the watch is water resistant. The Seiko Wave logo is engraved into the case, which serves as a reminder of this watch’s intended purpose. Sapphire crystal glass provides the watch with superlative scratch resistance and protection.

The Dial:

The dial of the SPB103J1 is presented in a glossy green tone. The simplistic layout of the dial ensures optimum legibility and avoids the risk of any complications. It consists of applied polished hour markers and an equally bold handset consisting of an short pointed hour hand and baton-style minute hand. Both the indices and handset have been filled with a luminescent material, allowing the wearer to read the time in the dark.

The date window at 3 o’clock gives the watch a classic divers feel, the neat positioning does not comprise the watch’s quintessential appeal. Around the age of the dial is a subtle black chapter ring that displays a 60-minute scale. The Seiko logo is presented in white beneath the 12 o’clock marker. 

The Bracelet:

The 3-link oyster style bestows the watch with an undeniable classic dive watch feel. The oyster bracelet is a style that was pioneered by Rolex and has since been used in a plethora of the worlds most celebrated dive watches, due to its simplistic, yet effective design,. Unlike the polished case, the bracelet is finished using a brushing technique. This created a subdued contrast between the bracelet and the dial. It is stainless steel, but it also comes with a free silicone strap, which is perfect for diving. The stainless steel bracelet fastens using a fold-over safety clasp. The buckle of the claps has features the Seiko logo.


Seiko’s 6R15 movement powers this timepiece, which offers a 70-hour power reserve. It consists of 23 Jewells and beats at 21,600 bph. The movement provides an accuracy range of +25/-15 seconds per day. It also offers the wearer the option of hand-winding and a hacking feature.  The watch is water resistant to 200 metres, which allows it to be worn when scuba diving.

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Additional information





Face Colour












Strap Colour





2 Year Manufacturer's Guarantee





Case Size


Strap Type

Stainless Steel

Water Resistency



Automatic (Self-Wind and Manual Wind)


Sapphire Crystal

Clasp Type

Standard Buckle

Lug Width


Bracelet Type

Three Link Oyster

Maximum Bracelet/Strap Length


Case Height









Seiko Watches


Seiko Prospex Watches


Mens Watches

Free Strap Adjustment

It's important that your watch fits your wrist comfortably and looks great at the same time.

Leather strap watches tend to fit without a problem for most wearers. However, watches fitted with metal bracelets often need adjusting to get the perfect fit.

This is generally a very simple procedure. We can do this for you, or you can get the watch adjusted locally.

Option 1. Specify your wrist measurement and we will adjust it before being sent

When purchasing a watch which has a metal bracelet with adjustable links, we will gladly adjust the watch bracelet to fit your wrist before sending the watch to you - free of charge!

Simply type your wrist measurement (in inches or centimetres) into the bracelet size section of the checkout and we will ensure the watch bracelet is adjusted accordingly before being sent to you. We will include all the surplus links, with the watch.

How to measure your wrist

You can measure your wrist with a piece of string which you can measure against a ruler:

You should allow about half a centimetre (1/4 inch) of slack to prevent it being too tight on your wrist.

In the event of you needing an extra-long wrist bracelet, which requires an extension to the original watch, we must obtain extra links from the manufacturer, and in this event, we will contact you to inform you of any possible delays or applicable charges.

Watches with bracelets adjusted by WatchNation are still eligible under our refund policy.

Option 2. Buy the watch online from WatchNation and have it adjusted locally

If you wish, you can have it adjusted locally by another jeweller or key cutter. However, you will have to cover the cost of this option yourself.

Delivery Information

Selling Price Royal Mail 48 (Tracked) Royal Mail 24 (Tracked) Royal Mail Special Delivery by 1pm Royal Mail Special Delivery by 9am
£0 to £30 £2.95 £3.95 £5.95 £12.95
£30.01 to £50 FREE £2.95
£50.01 to £300 N/A FREE
£300.01 or more N/A FREE

All orders are sent using Royal Mail's tracked delivery service. Orders placed before 4.00 pm (Monday-Friday) or 11.00 am Saturday are dispatched the same day. Sunday orders are dispatched on the following Monday.

We are pleased to offer worldwide shipping. For accurate shipping rates, please add the item to your basket. Once you enter your shipping address, you will be offered all shipping options.

All shipping rates include duties and taxes paid. The total price you see in the checkout, is all you will have to pay.

On average, a delivery to the EU will take between 3-5 working days and delivery to the rest of the world will take 5-7 working days.


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