AnchorFLEX™ End-Link Deployant

For Seiko Prospex SPB143 Series

Upgrade your Seiko Prospex SPB143 series dive watch with premium FKM rubber and end-links.

End links & spring bars included
Integrated curved-end look at the case
Fits 5.25″–8″ wrists
Soft FKM rubber, comfortable from day one

Shipping calculated at checkout.

Material: AnchorFLEX™ FKM rubber

Hardware: 316L Stainless Steel end-links and premium spring bars included.

Standard Precision clasp sold separately.

Fitment: Made for Seiko Prospex SPB143 series watches (SPB143, SPB145, SPB147, SPB149, and JDM SBDC101, SBDC103, SBDC105, SBDC107)

A deliberately tight fit. We spec the end thicker than most straps for strength, so seating the spring bars takes more force than you might expect. That's by design. Take your time on the first fitting.

Length: 3-piece strap with clasp ends (100mm/75mm) and one hole end (105mm) for maximum flexibility. Comfortably fits wrists from 5.25" to 8"

AnchorFlex™ End-Link: Deployant

Integrated look. Deployant security.

Fits the Seiko Prospex SPB143 series (SPB143, SPB145, SPB147, SPB149, and JDM SBDC101, SBDC103, SBDC105, SBDC107). Machined 316L end links and spring bars are included.

Made for Seiko's modern 62MAS. Precision-machined end links close the gap to the case for a clean integrated profile, and the 18mm Precision Deployant Clasp makes it secure and effortless to put on and take off.

The same Flagship rubber, shaped for an integrated fit

This is the AnchorFlex Flagship rubber you already know, cut to sit flush against the case and finished with a clasp that disappears on the wrist. No tail to tuck, no keeper to chase. It stays sized once you've set it.

Everything you need, in the box

No need to hunt down your original bracelet parts. Each strap comes with machined 316L end links cut for the SPB143 case, plus spring bars, so it's ready to install straight out of the box.

The right fit out of the box

Every deployant version ships as a 3-piece set: two clasp ends and one hole end. That means no guessing a size at checkout. Pick the combination that fits your wrist, and you're done.

Precision Deployant Clasp

18mm, machined from 316L stainless steel
Brushed and polished finishing to complement the SPB143 case
Available as an add-on on this page

Why FKM

FKM fluoroelastomer is what we build every AnchorFlex strap from, and it's why they last:

Holds up to UV, heat, and chemicals
Won't crack, fade, or go brittle with age
Soft and pliable against the wrist, but structured enough to keep its shape
No sagging or collapse the way cheap rubber does

Built on the Flagship profile

Clean modern lines with a subtle taper
Substantial enough for daily wear, refined enough to dress up
Built to complement a tool watch, not overpower it

It's the strap you leave on.

Specifications


Material	AnchorFlex FKM rubber
Fits	Seiko Prospex SPB143 series: SPB143, SPB145, SPB147, SPB149 / SBDC101, SBDC103, SBDC105, SBDC107 (40.5mm case, 20mm lugs)
End links	Machined 316L stainless steel, included
Spring bars	Included
Clasp	18mm Precision Deployant, 316L stainless steel (brushed/polished), available as an add-on
Length	3-piece: two clasp ends (75mm / 100mm), 105mm hole end
Wrist fit	5.25″–8″

FAQs

Some end-link installs can feel tight at first because the thickness rubber strap at the end-link is maximized to ensure durability. There are a few ways to get it installed:

First, try gently wiggling and pushing the spring bar through until the spring bar pops into the opposite side of the end link. This can require some effort.

You can also squeeze the rubber portion of the strap into the end link between your thumb and index finger while pushing the spring bar into place. This helps compress the rubber slightly and gives the spring bar more room to seat properly.

If those techniques do not work, our premium 1.7mm spring bars can be used as an alternative. There is no downside to using them, but we recommend trying the first two installation methods first since the standard spring bars usually work once everything is seated correctly.

If you still have trouble, contact us and we can help troubleshoot the install.

AnchorFLEX™ straps are made from premium FKM rubber and have been third-party tested to be free of harmful fluorinated “forever chemicals” within the scope of the testing performed. We do not intentionally add PFAS-based coatings, surface treatments, or chemical finishes to our straps. Because FKM is a fluorinated rubber, we avoid vague blanket claims and clearly disclose the material. Customers who prefer to avoid fluorinated rubber entirely may prefer our nylon, sailcloth, leather, or other non-FKM strap options.

AnchorFlex™ End-Link Deployant for Seiko Prospex SPB143 Series - Bathyscaphe Black