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SEIKO

Seiko SPB121 Prospex Men's Watch Brown 39.5mm Stainless Steel

  • Based on 83 reviews
Condition: New
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$725.00 Why this price?
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Availability: Only 1 left in stock, order soon!
Fulfilled by JustCalculators
Arrives Thursday, Apr 30
Order within 20 hours and 58 minutes
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Description

- Automatic Winding Capability - Magnified Date Window - LumiBrite Hands and Markers - Green Dial with Sunray Finish and Gold Accents - Rotating Bezel - Tri-Fold Clasp with Push Button Release - 39.5mm Case Diameter - 20mm Lug Width

Product Dimensions ‏ : ‎ 5 x 5 x 4 inches; 1.04 Pounds


Item model number ‏ : ‎ SPB121


Department ‏ : ‎ mens


Date First Available ‏ : ‎ June 2, 2022


Manufacturer ‏ : ‎ Seiko


Product Warranty: For warranty information about this product, please click here


Best Sellers Rank: #272,478 in Clothing, Shoes & Jewelry (See Top 100 in Clothing, Shoes & Jewelry) #913 in Men's Wrist Watches


#913 in Men's Wrist Watches:


Customer Reviews: 4.7 4.7 out of 5 stars (117)


Display: Analog


Watch Movement Type: Automatic


Additional Features: Second Hand


Power Source: Automatic


Strap Type: Leather Strap


Water Resistance Depth: 200 Meters


Sport Type: Walking


Clasp Type: Tri-fold clasp with push button release


Water Resistance Level: Waterproof


Embellishment Feature: Crystal


Closure Type: Push-Button


Style Name: Modern


Shape: Round


Band Color: Brown


Dial Color: Green


Theme: Sports


Pattern: Sunray


Face Style: Modern


Brand Name: SEIKO


Model Name: SPB121


Model Number: SPB121


Series Number: 121


Item Weight: 0.47 Kilograms


Manufacturer: Seiko


UPC: 029665200730


Manufacturer Part Number: SPB121


Age Range Description: Adult


Band Material Type: Leather


Case Material Type: Stainless Steel


Crystal: Sapphire


Case Diameter: 39.5 Millimeters


Band Width: 20


Case Thickness: 13 Millimeters


Warranty Type: Manufacturer


Frequently asked questions

If you place your order now, the estimated arrival date for this product is: Thursday, Apr 30

Yes, absolutely! You may return this product for a full refund within 30 days of receiving it.

To initiate a return, please visit our Returns Center.

View our full returns policy here.

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Top Amazon Reviews

    • Outstanding Watch, Shipping and Price
Love love love this watch! It is gorgeous. The sapphire crystal, the cathedral hands, the cyclops calendar, the green dial, the gold numerals, the super shiny bezel and lugs are all outstanding. The brown leather watch band is very secure with a locking closure and two tips at the front and the back of the bracelet for extra security. I have a very small wrist and this fit very well. This watch is only 1.5 mm larger than my Bulova field watch but does not look bigger. It, however, is more prominent on my wrist because of its height. The band fits much better than any other watch manufacture band. I read complaints about the band but with exception of the color, I don't wear much brown, I love it. The shipping was fast. I received it a day early. It was a great price for a great watch. Thank you Wristoutlet. ... show more
Reviewed in the United States on December 24, 2025 by EB
    • if you are looking for the 1 watch to wear forever, this is it
just made it to 8 months of daily wear with my alpinist that i bought in january. I have owned 1 or 2 automatics previous watches previously, but I was a mainly a Solar Quartz type of guy. i just like a level of accuracy that, up until now, automatics didnt really provide. The alpinist has proven to me its absolutely INSANE levels of accuracy and durability. It is bulletproof, period. The accuracy is excellent, period. It is, to me, the ultimate 1 watch to go anywhere and do anything. DESIGN - The time is very legible and quick to read even at a quick glance. for me, only the even number indices being arabic numerals just helps. maybe it is just me. Lume blew me away, I didnt realize that the lume was gonna be that good. Lumibrite aint no Super Luminova. at least none that i have seen. The compass is made fun of, and i can get it. I had thought it was like some form of magnetic compass and that the lower crown was a button, but thats not it at all. Its just a free spinning wheel that rotates the inner bezel. I set it along indices to mark the day of the week so it does have use to me. you can of course use this like any other bezel like on a dive watch, and you can mark whatever or use it to remember whatever you want. Since it is a free spinning bezel with no lock, it can spin out of place, however. just something to consider. As for the strap. Well... i dont like it. i replaced it with a nylon strap. it is 20mm so the world is yours when it comes to straps and bracelets. one thing i did note was that the alpinist does NOT like quick release bars. They like to get stuck and twist and pull on the strap. The alpinist does come with spring bars, but i went ahead and ordered some big boy thick durable ones and all my bar problems went away. DURABILITY - my type of work is not in the office. it involves being pretty physical, and i have not gained the first scratch on my crystal. the sapphire is excellent. I have acquired plenty of scratches on the polished stainless steel, though. i live with it okay, but polished stainless would not let the scratches stand out as well. otherwise, the diashock movement is bulletproof, and i have had ZERO issues with durability THE MOVEMENT - If you do any research online, you will find that some people complain about the 6R35. Their main complaints being the accuracy ratings from Seiko, and Positional Variance. IN MY EXPERIENCE, i have had extremely precise levels of accuracy. I figured out by setting my watch, fully wound, down in different positions, that setting my watch down flat gains about 5 to 6 seconds per day. when i set my watch upright, or vertical, it loses about 5 seconds per day. so what i just do is if i see my watch is running fast, i set it down upright, and if its slow, set it flat. this has let me keep accuracy within 5 seconds for incredible periods of time for an automatic. I accidentally pulled the crown out all the way changing the date to the first for July. I last pulled it out february. it blows my mind. the gshock and f91w that i set to keep track of perfect time, i have had to set multiple times before i had to pull the crown out of the alpinist. Keeping the watch fully wound, worn everyday, and placed in the right positions has given me incredible results. now, if i remove the crown for any reason, i have noticed it wanting to run a bit faster than usual, and i wouldnt call it unpredictable, but it is definitely different. i assume what people do is set the time, see its fast, and just set it because thats what you do with an automatic, then it got set again and now its gonna run silly for like a day or two. if that was all i saw for results, i would call it inaccurate too. I say all of this because i believe it matters a great deal how you are gonna wear this watch. This is my one single, EDC, Go anywhere do anything, watch that i rarely rotate. the power reserve will let you rotate a day or two of other watches, but this watch works best if you never let it die or be reset. it gives you the ability to do that, in what i have seen, but is that right for you? thats up to you. if i rotated many watches and it may be a while before i wear this watch again, maybe i would say its not worth it. all in all, for me, this watch is PERFECT. this watch has been so good its flipped my opinion of automatics as a whole. if this is gonna be your 1 watch that you have forever, this will do you right. ... show more
Reviewed in the United States on August 14, 2025 by Kenny
    • Absolute banger of a watch
Beautiful! Not as big and bulky as it looks in the pictures. Looks sporty and versatile with lots of class, and goes well with a ton of different bands. Get compliments all the time
Reviewed in the United States on February 2, 2026 by MARP
    • Beautiful watch, Great seller.
This is a beautiful watch at a great deal. Is was delivered earlier than expected and packed with care.
Reviewed in the United States on February 18, 2026 by David Venti
    • Amazing watch!
Collectors watch. Compliments every time!
Reviewed in the United States on January 26, 2026 by Huh?
    • Alpinist
Excellent seller and great communication. Great watch as advertised. Will do business again.
Reviewed in the United States on January 7, 2026 by Addyth
    • good watch
keeps the time well, looks good but the strap is bad and needs to be ditched right away. keep that in mind when purchasing the alpinist. its also a bit thicker then expected so remember this is a thick one. if seiko used a decent strap then its 5 stars
Reviewed in the United States on December 18, 2025 by blaster
    • Once you change the strap it looks amazing
Review Image by Sebastian
Review Image by Sebastian
Once you change the strap it looks amazing
Reviewed in the United States on March 20, 2026 by Sebastian

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