---
product_id: 446575923
title: "SPB121 Prospex Men's Watch Brown 39.5mm Stainless Steel"
brand: "seiko"
price: "178383 kr"
currency: ISK
in_stock: true
reviews_count: 13
category: "Seiko"
url: https://www.desertcart.is/products/446575923-spb121-prospex-mens-watch-brown-39-5mm-stainless-steel
store_origin: IS
region: Iceland
---

# 70-hour power reserve Magnified date window Screw-down crown for water resistance SPB121 Prospex Men's Watch Brown 39.5mm Stainless Steel

**Brand:** seiko
**Price:** 178383 kr
**Availability:** ✅ In Stock

## Summary

> ⌚ Elevate your wrist game with the Seiko SPB121 – where precision meets prestige.

## Quick Answers

- **What is this?** SPB121 Prospex Men's Watch Brown 39.5mm Stainless Steel by seiko
- **How much does it cost?** 178383 kr with free shipping
- **Is it available?** Yes, in stock and ready to ship
- **Where can I buy it?** [www.desertcart.is](https://www.desertcart.is/products/446575923-spb121-prospex-mens-watch-brown-39-5mm-stainless-steel)

## Best For

- seiko enthusiasts

## Why This Product

- Trusted seiko brand quality
- Free international shipping included
- Worldwide delivery with tracking
- 15-day hassle-free returns

## Key Features

- • **Secure & Sleek:** Screw-down crown ensures water resistance and durability for your active lifestyle.
- • **Precision at a Glance:** Magnified date window and LumiBrite hands deliver effortless readability anytime.
- • **Timeless Style Statement:** Green sunray dial with gold accents and polished stainless steel bezel for standout sophistication.
- • **Comfort Meets Versatility:** 39.5mm case with 20mm lug width fits perfectly on any wrist, ready for any strap swap.
- • **Endurance that Outlasts Your Day:** 70-hour power reserve keeps you powered through busy workweeks without winding.

## Overview

The Seiko SPB121 Prospex Men's Watch combines a robust 70-hour automatic power reserve with a secure screw-down crown and a magnified date window for enhanced usability. Featuring a striking green sunray dial with gold accents, LumiBrite hands, and a 39.5mm stainless steel case, this watch balances durability and style for the modern professional. Its versatile 20mm lug width allows for easy customization, making it the ultimate everyday timepiece for those who demand accuracy and elegance.

## 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

Review: 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.
Review: 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.

## Features

- Screw-down crown, screw, see-through caseback, 70 hour power reserve, magnified date window, LumiBrite hands and markers

## Technical Specifications

| Specification | Value |
|---------------|-------|
| ASIN  | B0B33H4V74 |
| Best Sellers Rank | #176,538 in Clothing, Shoes & Jewelry ( See Top 100 in Clothing, Shoes & Jewelry ) #555 in Men's Wrist Watches |
| Customer Reviews | 4.6 4.6 out of 5 stars (97) |
| Date First Available  | June 2, 2022 |
| Department  | mens |
| Item model number  | SPB121 |
| Manufacturer  | Seiko |
| Product Dimensions  | 5 x 5 x 4 inches; 1.04 Pounds |

## Images

![SPB121 Prospex Men's Watch Brown 39.5mm Stainless Steel - Image 1](https://m.media-amazon.com/images/I/61CWhZouXiL.jpg)

## Questions & Answers

**Q: How can I be sure of that is original watch?**
A: I don’t believe they are making knock offs of a watch under a 1000.00 dollars

## Customer Reviews

### ⭐⭐⭐⭐⭐ Outstanding Watch, Shipping and Price
*by E***B on December 24, 2025*

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.

### ⭐⭐⭐⭐⭐ if you are looking for the 1 watch to wear forever, this is it
*by K***Y on August 14, 2025*

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.

### ⭐⭐⭐⭐⭐ Highly Recommended
*by C***7 on January 7, 2026*

This was a gift for my son. Item arrived on the date it was supposed to, fully packaged with Seiko packaging and protection on the watch surfaces. The Alpinist looks far better in person. Gives the appearance of a watch twice it's price. I have never been dissapointed with Seiko watches, especially Automatics. This one is Sporty yet formal. I would not feel out of place wearing it with a suit.

## Frequently Bought Together

- Seiko SPB121 Prospex Men's Watch Brown 39.5mm Stainless Steel
- Bergeon 4040 Extensible and reversible movement holder Watchmaker Tools
- BERGEON 8008 Rubber Ball to Open and Close case Backs Ø65 mm, black,white, Open

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*Product available on Desertcart Iceland*
*Store origin: IS*
*Last updated: 2026-01-27*