The movement, dressed. GS 9SA5 in yellow gold. Seen through the caseback.
A decorated rotor turns the one moving part you see through an exhibition caseback — the weight that swings as you wear the watch — into the finished centrepiece of the movement.
This is a drop-in NH movement rotor — GS 9SA5, finished in yellow gold by PVD (physical vapour deposition), so the colour is part of the metal's surface, not a layer of paint that can chip or peel.
Swapping it is the simplest mod there is — a single screw, no movement surgery, no watchmaker.
One screw. Two minutes.
You're not opening the movement — just trading the bare oscillating weight for a decorated one.
Seen through the caseback.
The rotor is the first thing the eye lands on behind an exhibition sapphire — the part that moves. Decorate it and the whole movement reads as considered.
PVD, not paint.
The yellow gold is laid down by physical vapour deposition — bonded into the surface, not brushed on. It won't flake, and it can't be stripped back to bare steel.
A two-minute mod.
It seats on the rotor post and holds with a single screw. No movement disassembly, no special tools, no risk to the calibre.
Built for the NH family.
Machined to Seiko's OEM rotor geometry — 0.15mm thicker to carry the CNC decoration — and tested to fit the full NH, 4R and 7S automatic line.
To see it, you'll want
An exhibition caseback. A decorated rotor only shows behind a sapphire (exhibition) caseback — a solid steel caseback hides the movement entirely.
A matching bridge. For the complete look, pair the rotor with a decorated NH movement bridge in the same finish.
Finish & Build
Compatibility
To allow for CNC decoration, the decorated rotor is 0.15mm thicker than the Seiko OEM rotor. Each rotor is tested to fit all our bridges, cases and casebacks.
Below is Seiko's technical drawing . As long as the case and caseback follow Seiko's OEM specification — a 0.4mm gap between the rotor and caseback — the rotor fits. If those parts deviate from Seiko OEM dimensions, the rotor may be incompatible.
All photos of watches with modification parts are for illustration purposes only and are not included with modification parts purchased.
Fitting a rotor is the easiest mod there is:
New to modding? Start with Seiko Modding: The Complete Build Guide , or browse NH Movements to build around it.
Everything worth knowing before you build.
This yellow gold movement rotor enhances NH35 movements with exceptional build quality and stunning appearance. Customers praised it as "perfect" with "insane quality" that "brings bling" to basic movements. Ideal for watch modifications and exhibition case backs. Fast delivery consistently noted. Universally recommended with perfect 5-star ratings across all reviews.
The build quality and the looks are very good I recommend it!
I used this rotor to upgrade the look of the otherwise basic movement on the Seiko 5 SRPE55. Very nice quality and a great improvement in appearance. I paid for express shipping but was still surprised by how fast it was shipped and delivered!
Stunning!!! Highly recommend buying this Rotor for your build.
Great products and super fast delivery time!!
The quality is insane, very good product. DHL EXPRESS not even one week and I get my package. The packaging was also fine.
Beautiful rotor
Fantastic rotor. Really brings some bling to a pretty bland NH35 movement.
I bought this rotor for an old Presage and it is great looking, thank you very much
Very well made and just gives the movement that extra pop in the exhibition back. Highly recommended
Hi please can you let me know when you have the GS 9SA5 yellow gold rotor back in stock? I’d love to get one for my NH35 movement.
Hi there,
Thank you for expressing interest in our mod parts!
Unfortunately, the GS 9SA5 Yellow Gold rotor has been discontinued and will not be restocked.
Hope this helps. Let me know if you have any other questions or if you'd like recommendations for alternatives.
Best regards,
Adriel
Lucius Atelier | SEIKO Mod Parts
How is the gold colour applied? Is it heat treated to a certain temperature that the steel changes colours, or is it a PVD coating?
Hello Jeffrey!
Thank you for expressing interest in our mod parts!
PVD Coating.
Hope this helps. Let me know if you have any more questions.
Cheers,
Adriel
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