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Seiko SPB143 Specifications
| Reference | SPB143, SPB143J1 |
|---|---|
| Case Size | 40.5mm |
| Lug Width | 20mm |
| Lug-to-Lug | 47mm |
| Thickness | 13.2mm |
| Case Material | stainless steel |
| Crystal | sapphire (dual-curved) |
| Water Resistance | 200m |
| Movement | 6R35 (automatic) |
| Bezel | rotating dive bezel |
| Crown | screw-down |
| Case Back | exhibition (see-through) |
| Price Range | $1,050-$1,300 |
Compatible Straps for the Seiko SPB143
The SPB143 uses a 20mm Lug Width and is compatible with the following strap types.
| Type | Recommended Brand | Why It Works | Price Range | Link |
|---|---|---|---|---|
| NATO/ZULU | Strapcode | Classic look, easy to swap, fits 20mm lugs | $15–$80 | |
| rubber/silicone | Crafter Blue | Water-resistant, comfortable for daily wear | $15–$80 | |
| oyster bracelet | Uncle Seiko | Sporty bracelet, solid end links available | $15–$80 | |
| jubilee bracelet | Barton | Classic bracelet style, comfortable links | $15–$80 | |
| leather | Archer | Dresses up the watch, fits 20mm lugs | $15–$80 |
Replacement Parts for the Seiko SPB143
| Part | Description | Compatibility Note |
|---|---|---|
| bezel insert | Outer ring marking | Matches rotating dive bezel configuration |
| crown with stem | Time-setting knob on case side | screw-down type |
| spring bars | Pins that hold the strap to the case | 20mm, 1.5mm diameter recommended |
| case back gasket | Seal that maintains water resistance | Required for 200m WR rating |
Modding the Seiko SPB143
The SPB143 is a popular platform for modding. Here are the most common modifications.
- strap swap — Upgrade to a premium aftermarket strap or metal bracelet.
- bezel insert — Swap the stock bezel insert for a ceramic, lumed, or differently colored option.
Frequently Asked Questions
What lug width is the Seiko SPB143?
The Seiko SPB143 has a 20mm lug width.
Is the SPB143 based on the original 62MAS?
Yes. The SPB143 is a modern reinterpretation of Seiko's first dive watch, the 62MAS from 1965. It shares the slim profile and case shape but uses the modern 6R35 movement.
What movement does the SPB143 use?
The SPB143 uses the Seiko 6R35 automatic movement with 70 hours of power reserve, hacking, and hand-winding.