Seiko Prospex Willard SPB237 · Ref. SEIKO PROSPEX WILLARD SPB232025 · 17mm lug
At a Glance
| # | Best For | Strap | Material | Thickness |
|---|---|---|---|---|
| 1 | Overall / First Purchase | White Chevre Slim Strap | Chèvre | 2.2mm |
| 2 | Dressy / Formal | Matte White Alligator Signature Strap | Alligator | 4.5–2.2mm |
| 3 | Everyday / Casual | Taupe Buttero Slim Strap | Buttero Calfskin | 2.2mm |
| 4 | Minimalist / Refined | Green Shell Cordovan Slim Strap | Shell Cordovan | 2.2mm |
| 5 | Casual / Relaxed | Brown Waxy Slim Strap | Waxy Leather | 2.2mm |
| 6 | Active / Sporty | Moss Green Babele Slim Strap | Babele Calfskin | 2.2mm |
| 7 | Comfort / Wildcard | Dark Grey Chevre Slim Strap | Chèvre | 2.2mm |
What makes the Seiko Prospex Willard SPB237 (ref. SEIKO PROSPEX WILLARD SPB232025) special is not just one thing — it is the combination. The movement inside is refined, precise, and built to last. The finishing and attention to detail speak for themselves. And at 17mm lug width, it is a watch that rewards experimentation with straps.
The case with its profile gives you just enough wrist presence to anchor different strap materials without the watch disappearing. Here are my 7 picks — and why each one works.
Quick Specs
| Case diameter | |
| Lug width | 17mm |
| Lug-to-lug | |
| Case thickness | |
| Water resistance | |
| Crystal | |
| Case material | |
| Movement |
The 17mm lug width means your options are curated but well-covered. Already know what you're looking for? Browse all Seiko Prospex Willard SPB237-compatible straps on the Strap Finder →
1. Best Overall — White Chevre Slim Strap
Your first strap upgrade should feel like an obvious improvement. This one does.
The White Chevre Slim Strap is made from chevre (goatskin) leather, sourced from the Alran tannery. The natural pebbled grain is finer than Epsom and slightly shiny — it looks luxurious without trying too hard. Chevre is also impressively water and scratch resistant for a natural leather. At 2.2mm thick, it balances presence and wearability nicely.
The Seiko Prospex Willard SPB237's case is ideally proportioned for this strap. Whether you are wearing it casually or dressing it up, the combination feels intentional. It is the kind of pairing where both the watch and strap look better together than apart.
The kind of strap that earns a permanent spot in your rotation.
If this style appeals but you want a different tone:
- Light Grey Chevre Slim Strap
- Colibri Chevre Slim Strap
- Lavender Chevre Slim Strap
- Gold Chevre Slim Strap
2. Best Dressy — Matte White Alligator Signature Strap
When you need to dress the Seiko Prospex Willard SPB237 up, this is the strap that delivers.
The Matte White Alligator Signature Strap is crafted from genuine alligator leather — not embossed calfskin, the real thing. Each scale pattern is unique, and the matte finish gives it a refined presence that catches light without being flashy. The leather is supple from the start with minimal break-in needed. At 4.5–2.2mm thick, it balances presence and wearability nicely.
On the Seiko Prospex Willard SPB237, this strap preserves the watch's go-anywhere character. The case at thick pairs naturally with the padded construction without creating any imbalance on the wrist.
A combination that's greater than the sum of its parts.
Worth a look in other colourways:
- Matte Black Alligator Signature Strap
- Matte Navy Alligator Signature Strap
- Matte Himalayan Alligator Signature Strap
- Matte Mahogany Alligator Signature Strap
3. Best Everyday — Taupe Buttero Slim Strap
For daily wear, comfort and versatility matter more than anything else.
The Taupe Buttero Slim Strap features Buttero leather from the Walpier tannery in Italy. This vegetable-tanned leather develops one of the most beautiful patinas in watchmaking — scratches blend into the surface and the colour deepens over time. If you enjoy watching your strap age gracefully, this is the one. At 2.2mm thick, it balances presence and wearability nicely.
Paired with the Seiko Prospex Willard SPB237's distinctive dial, this strap adds a layer of personality that the factory option does not offer. The case thickness means a padded strap like this one feels proportional and substantial.
It's the kind of pairing that makes you wonder why you didn't try it sooner.
Other colours worth considering:
- Chestnut Buttero Slim Strap
- Brown Buttero Slim Strap
- Natural Buttero Slim Strap
- Green Buttero Slim Strap
4. Best Minimalist — Green Shell Cordovan Slim Strap
Sometimes less is more. This strap proves it.
The Green Shell Cordovan Slim Strap is crafted from premium materials with careful attention to detail and construction quality. At 2.2mm thick, it balances presence and wearability nicely.
On the Seiko Prospex Willard SPB237, this strap preserves the watch's go-anywhere character. The case at thick pairs naturally with the padded construction without creating any imbalance on the wrist.
A combination that's greater than the sum of its parts.
Worth a look in other colourways:
- Black Shell Cordovan Slim Strap
- Navy Shell Cordovan Slim Strap
- Cognac Shell Cordovan Slim Strap
- Natural Shell Cordovan Slim Strap
5. Best Casual — Brown Waxy Slim Strap
Weekend straps should feel effortless. This one nails that.
The Brown Waxy Slim Strap features waxy pull-up leather with a rich, oily finish that shifts and lightens with wear. The resulting patina is what leather enthusiasts live for — a lived-in character that cannot be replicated by any other material. At 2.2mm thick, it balances presence and wearability nicely.
The Seiko Prospex Willard SPB237's case is ideally proportioned for this strap. Whether you are wearing it casually or dressing it up, the combination feels intentional. It is the kind of pairing where both the watch and strap look better together than apart.
The kind of strap that earns a permanent spot in your rotation.
6. Best Sporty — Moss Green Babele Slim Strap
When you want your Seiko Prospex Willard SPB237 to feel more relaxed and sporty, this is the pick.
The Moss Green Babele Slim Strap features Buttero leather from the Walpier tannery in Italy. This vegetable-tanned leather develops one of the most beautiful patinas in watchmaking — scratches blend into the surface and the colour deepens over time. If you enjoy watching your strap age gracefully, this is the one. At 2.2mm thick, it balances presence and wearability nicely.
On the Seiko Prospex Willard SPB237, this strap preserves the watch's go-anywhere character. The case at thick pairs naturally with the padded construction without creating any imbalance on the wrist.
A combination that's greater than the sum of its parts.
Worth a look in other colourways:
- Natural Babele Slim Strap
- Jean Grey Babele Slim Strap
- Mocha Babele Slim Strap
- Denim Babele Slim Strap
7. The Wildcard — Dark Grey Chevre Slim Strap
This one's different — and that's exactly the point.
The Dark Grey Chevre Slim Strap is made from chevre (goatskin) leather, sourced from the Alran tannery. The natural pebbled grain is finer than Epsom and slightly shiny — it looks luxurious without trying too hard. Chevre is also impressively water and scratch resistant for a natural leather. At 2.2mm thick, it balances presence and wearability nicely.
On the Seiko Prospex Willard SPB237, this strap preserves the watch's go-anywhere character. The case at thick pairs naturally with the padded construction without creating any imbalance on the wrist.
The kind of strap that earns a permanent spot in your rotation.
If this style appeals but you want a different tone:
- Light Grey Chevre Slim Strap
- Colibri Chevre Slim Strap
- Lavender Chevre Slim Strap
- Gold Chevre Slim Strap
A Note on Buckle Colour
Quick but important: always match your buckle to your case. The Seiko Prospex Willard SPB237's case calls for a silver (brushed or polished) buckle. All Delugs leather straps ship with a pin buckle and can be upgraded to a Spring Deployant Clasp for extra security and convenience. All Delugs straps come with quick-release spring bars pre-installed, so swapping straps takes seconds.
How to Change the Strap on Your Seiko Prospex Willard SPB237
Swapping straps on the Seiko Prospex Willard SPB237 is one of the easiest upgrades you can make — and with Delugs straps, you don't even need a tool.
If your Seiko Prospex Willard SPB237 came on a bracelet, you'll first need to remove it. The easiest way to do this at home is with a Bracelet Removal Tool, which lets you compress the spring bars without risking scratches to the lugs or caseback. Once the bracelet is off, you can slide your new Delugs strap straight in.
All Delugs straps come with quick-release spring bars already pre-installed, so changing straps is completely tool-free. Here's how:
- Prepare your workspace. Lay the watch face-down on a soft cloth or microfiber pad to protect the caseback from scratches.
- Release the spring bar. Locate the small lever on the quick-release spring bar. Pull it back with your fingernail or fingertip to compress the bar.
- Remove the strap. While holding the lever, angle the strap out from between the lugs. Repeat for the other side.
- Insert the new strap. Slide one end of the spring bar into the lug hole. Pull the lever on the quick-release spring bar knob, guide the entire spring bar into the opposite lug hole, and then release the knob. You should hear a small click when the spring bar extends and seats into the lug hole.
- Check the fit. Give the strap a gentle tug to make sure both spring bars are securely locked in. If there's any play, reseat the spring bar.
The entire process takes under a minute once you get the hang of it — no spring bar tool required. The Seiko Prospex Willard SPB237 uses a standard 17mm lug width, and all Delugs straps in 17mm will fit perfectly.
Frequently Asked Questions
What is the lug width of the Seiko SEIKO PROSPEX WILLARD SPB232025?
The Seiko SEIKO PROSPEX WILLARD SPB232025 has a 17mm lug width. While 17mm is less common than 20mm, there is still a strong selection of quality straps available. All Delugs straps are available in 17mm.
What is the reference number for the Seiko Prospex Willard SPB237?
The reference number for the Seiko Prospex Willard SPB237 is SEIKO PROSPEX WILLARD SPB232025. You can find this on the caseback of your watch or on the original paperwork. Knowing your reference number helps ensure you get the right lug width when ordering a strap.
Can I use a dressy leather strap on a Seiko versatile watch?
The Prospex Willard SPB237 is one of the most versatile watches in the Seiko lineup — it takes both dressy and casual straps equally well. That's part of what makes it such a rewarding watch for strap changes. Don't be afraid to experiment.
Do Delugs straps come with spring bars?
Yes — every Delugs strap comes with quick-release spring bars pre-installed. This means you can change straps by hand in seconds, without needing any tools. The quick-release mechanism uses a small lever that you pull with your fingertip to compress the spring bar.
What is the best strap material for the Seiko Prospex Willard SPB237?
The Prospex Willard SPB237's versatile nature means it works with almost everything. Start with what matches your most common wearing occasion — rubber or sailcloth for active use, nubuck or waxy leather for everyday, and alligator or saffiano for dressier moments. The Strap Finder makes it easy to browse by material and style.
Does Seiko use quick-release spring bars?
Most Seiko watches use standard spring bars that require a tool to remove. All Delugs straps come with quick-release spring bars pre-installed, so once you make the switch, future changes are completely tool-free.
Where can I find straps compatible with the Seiko SEIKO PROSPEX WILLARD SPB232025?
The Seiko Strap Finder shows every Delugs strap compatible with the SEIKO PROSPEX WILLARD SPB232025, filtered by lug width and style. You can also use the general Strap Finder to browse by brand, collection, and material. If you need help choosing, our team is available 24/7 via live chat.
Finding Your Strap
The beauty of the Seiko Prospex Willard SPB237 is that it rewards experimentation. A dressy alligator for the office, nubuck for the weekend — each strap brings out a different side of the watch.
Use the Seiko Prospex Willard SPB237 Strap Finder to see every compatible strap in one place, filtered to your exact reference. Or if you'd rather explore by feel, the general Seiko Strap Finder lets you browse the full lineup and find your match.
Not sure which strap is right for your specific Prospex Willard SPB237? Our team is available 24/7 via live chat — drop us a message and we'll help you find the perfect match for your watch, wrist size, and style.
About Delugs
Founded in 2018 and headquartered in Singapore, Delugs is dedicated to elevating the experience of watch ownership through the simple yet powerful act of strap changing. We believe that straps are integral to how a timepiece is worn, perceived, and enjoyed. Our mission is to make strap changing a lifestyle — an everyday act of self-expression and versatility.
Delugs is an independent brand with a global community of clients, with a strong online presence and growing physical retail footprint. Our direct-to-consumer focus keeps us closely connected with the watch enthusiast community — fostering conversations, hosting events, and helping shape a more inclusive and expressive culture around watch collecting. We also work closely with watch brands to craft straps that complement their timepieces, bridging the gap between brand and collector, form and function.
Our catalogue spans leather, rubber, and fabric straps, with options for every watch and every occasion. We are committed to craftsmanship and quality, product design and innovation, and outstanding customer service. We offer watch owners the freedom to change straps as easily as changing outfits, and the opportunity to engage more deeply with the watches they love.
Visit our flagship boutique at Raffles Hotel, Singapore →
— Marcus
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