Seiko Lassale 5A54-5149 Tank Gold-Plated — Ultra-Thin 4mm (1984)
Only 1 available
Shipping from Europe — taxes and customs duties are the buyer's responsibility outside the EU
Lifetime authenticity guarantee
Serviced movement & 1 year warranty
International shipping
Photo taken on a 17.5 cm wrist
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Atelier Note
Four millimetres thick, bracelet included in the profile — and a name acquired in 1979 from the Geneva watchmaker that held the record for the thinnest movement in the world.
A 1984 Lassale, the ultra-thin that Seiko signed without its own name
This watch bears a name with a story: Lassale. Jean Lassale was a Geneva watchmaker famous for an absolute record — calibre 1200, a mechanical movement measuring 1.2mm thick, the thinnest ever built. When it went bankrupt in 1979, Seiko acquired the house and in 1981 launched the Seiko Lassale line: its ultra-thin luxury showcase for the West, sister to the Credor line reserved for Japan. On the dial, a single name: LASSALE — Seiko stepped aside in favor of its finest line.
This 5A54-5149 reference, dated November 1984, is its exact expression: a gold-plated tank measuring 22.5mm, just 4mm thick, bracelet included. The case is reduced to a frame — two horizontal bars holding the dial, no bezel, almost no sides.
The brushed golden dial is treated in the same material as the case: baton hour markers as fine as ruler lines, the LASSALE signature, the QUARTZ mention, and two golden baton hands. Nothing else — at this thickness, every element matters.
The original integrated woven bracelet extends the frame seamlessly: a herringbone gold weave flowing over the wrist like a braid, secured by its original Buckle over 19cm, to be sized by removing links. The movement is a Seiko quartz calibre 5A54, ultra-thin, developed for these luxury lines — checked and fitted with a new battery.
Three points to note
01
4mm thick — the ultra-thin profile, the very reason for the Lassale line, inherited from the Geneva record-holder for slimness.
02
Original integrated herringbone bracelet — a woven gold braid, made in one piece with the case.
03
Signed Lassale alone — Seiko's export luxury showcase, launched in 1981, the Western sister to Credor.
Why choose a vintage Seiko Lassale?
This vintage Seiko watch holds a distinctive place among vintage men's and women's watches : its 22.5mm tank format and integrated mesh bracelet make it a horological jewel for everyday wear, signed by a line that Seiko positioned at the top of its Western catalogue — and that few people still know how to name. That is precisely what makes it valuable.
Like all our vintage quartz watches, this one has been opened and checked by our partner watchmakers: movement verification, examination of the dial, hands and case. Every vintage watch we offer comes with an Atelier Victor invoice serving as a certificate, a one-year guarantee, and guaranteed lifetime authenticity.
→ Discover our other vintage Seiko watches
→ See all our vintage Japanese watches
Technical specifications
- Brand: Seiko Lassale
- Model: Tank ultra-thin
- Reference: 5A54-5149
- Serial number: 4N44••
- Year: 1984 (November)
- Origin: Japan
- Gender: Men's and women's watch (Unisex)
- Movement: Seiko quartz, 5A54 ultra-thin calibre
- Functions: Hours, minutes
- Case: Gold-plated, steel caseback, framed tank shape
- Width: 22.5mm (23mm with crown)
- Lug to lug: 29mm
- Thickness: 4mm
- Lug width: 21mm
- Crown: Steel, original
- Dial: Brushed golden, baton indices, Lassale signature, original
- Hands: Golden batons, original
- Crystal: Mineral (condition 9/10)
- Bracelet: Integrated chevron-woven mesh, 19cm, adjustable by removing links, original
- Buckle: Gold-plated, original
Condition and guarantee
- Overall condition: Very well preserved condition. Clean golden dial, indices and hands without alteration, Crystal in very fine condition. The case and mesh show light signs of use, visible in our photographs; the weave is complete, supple, and the plating even.
- Water resistance: Not guaranteed (vintage watch)
- Authenticity: Lifetime guarantee
- Mechanics: Checked quartz movement, new battery, guaranteed for 1 year
- Included: Atelier Victor invoice
- Not included: Original box and papers
Frequently asked questions
What is Seiko Lassale?
It is the luxury line that Seiko launched in 1981 for Western markets, after acquiring the Geneva house Jean Lassale in 1979 — the watchmaker behind calibre 1200, the thinnest mechanical movement in the world at 1.2mm thick. Seiko took over the name and the vocation: ultra-thin dress watches, positioned at the top of its export catalogue, just as the Credor line was in Japan. The line has since disappeared, and its watches rarely circulate.
Why is this watch so thin?
Because that is its very purpose: 4mm thick, achieved through an ultra-thin quartz caliber, a case reduced to a frame and only two hands — no seconds hand, no date. At such slenderness, the watch disappears beneath a cuff and wears like a bracelet. It is the direct legacy of Jean Lassale, transposed into quartz by Seiko.
Why does the dial not bear the name Seiko?
It was the house’s choice: on its export luxury line, Seiko stepped back behind the sole name Lassale, just as it did with Credor in Japan. The caseback, however, bears the full Seiko references — this is how these watches are authenticated, and this one is perfectly consistent.
How is the bracelet sized?
The woven mesh measures 19cm and is adjusted by removing links: a watchmaker cuts the bracelet to the exact wrist length, as is customary with fine mesh bracelets. The operation is permanent — please let us know your wrist measurement at the time of purchase, and we will deliver the watch ready to wear, or untouched if you prefer to have it adjusted yourself.
Is this piece suitable for a slim or larger wrist?
At 22.5mm wide, 29mm Lug-to-lug and 4mm thick, it is a jewelry format — the 19cm mesh can be sized to the exact measurement, up to around 18cm. A guideline, never a rule: everyone wears what they like. Worn by a man, it conveys absolute purity beneath the cuff; by a woman, a full-fledged gold bracelet.
Mechanical warranty — 1 year
Each watch is inspected by our watchmakers before shipping. In case of a mechanism malfunction during the first year, we cover the repair.
Authenticity warranty — lifetime
If a watch turns out to be non-authentic, we will take it back and refund you in full. Without time limit.
What is not covered
- Exposure to water or humidity
- Shocks, impacts, or vibrations
- Consumable parts (strap, Crystal, crown, pushers)
- Battery replacement (quartz movements)
- Opening or disassembly of the watch by a third party
- Improper use
The accuracy of vintage watches varies according to the model, movement, and year of production. A request for accuracy improvement deemed within acceptable tolerances cannot be covered by the warranty.
Shipping fees
After-sales service is free. Shipping fees outside the United Arab Emirates remain the responsibility of the customer.
Authentication Process
Each watch is examined by our partner watchmakers before being offered for sale: verification of authenticity, checking the conformity of the components, identification of any modification or replacement of original parts.
If any element has been replaced during the life of the watch (dial, hands, crown, Crystal, strap), we systematically indicate it in the product sheet. You buy knowing the exact history of your piece.
Certificate of Authenticity
Your Atelier Victor invoice serves as a certificate of authenticity: it attests to the origin and conformity of the piece, and is covered by our lifetime authenticity guarantee — if a piece sold by Atelier Victor were found to be non-authentic, it would be fully refunded, with no time limit.
We accept several payment methods:
- Bank card (Visa, Mastercard, American Express)
- Bank transfer (AED, EUR, USD)
- Cryptocurrency (USDT, USDC)
- PayPal
Other currencies accepted upon request. Exchange fees of approximately 3% may apply.
A 3% discount is granted for any payment by bank transfer from €1,000.
Does the strap not suit you? Add the strap of your choice to your order: we will fit it to your watch before shipment, at no fitting charge.
International Shipping
Shipped within 48 to 72 business hours by DHL Express or an equivalent carrier depending on the destination. Delivery in 2 to 6 business days. Each shipment is insured and delivered against signature.
- Free delivery from €1,000 of purchase, as well as on the Jewelry Atelier Victor
- Tracking number sent as soon as the shipment is dispatched
- For certain destinations, delivery may be made to a secure collection point in order to guarantee the integrity of the shipment
Pickup in Dubai
Hand delivery by appointment in Downtown, Dubai. Make an appointment.
Taxes and Customs
The shipping origin is indicated on each product sheet. If the delivery country differs from the shipping country, customs duties and taxes may apply upon receipt, at the buyer's expense. In exceptional situations, customs checks may extend the delivery time, regardless of our wishes and those of the carrier.
For full details, please consult our shipping policy.
FINAL SALES
All sales are final: no return, exchange, or cancellation is accepted after order confirmation. Each piece is authenticated, inspected, and described in detail before being offered for sale.
BEFORE PURCHASE
Our advisors remain at your disposal for any questions and can send you additional photographs or videos upon simple request, by email or on WhatsApp.
NON-CONFORMING ITEM
In the exceptional case of an item that does not match its listing, please notify us within 72 hours: it will be eligible for a refund or an exchange. If the parcel shows damage upon delivery, it should be refused or its opening filmed continuously.
For full details, please consult our return policy.
A piece selected by Atelier Victor
Authenticated, checked, and photographed by us. As all sales are final, our team remains available 7 days a week on WhatsApp to answer your questions, share additional photos or a video of the piece in hand — so that your choice can be made with complete peace of mind.
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