Longines Ultra-Chron Ref.8508-1 Cal.6651 34.0mm 1974

Made as part of Longines’ dedication to creating the most accurate automatic watch in the world, came the iconic Longines Ultra-Chron line. With this very rare reference 8508-1 coming in a near immaculate square case with its original integrated bracelet. A true collectors piece for those with a special eye for the rare and unique.

Inside would be the much well regarded high beat calibre 6651 movement, ticking at an impressive 28,800vph creating a silky smooth seconds sweep. Having been freshly serviced in June 2025, the watch runs excellently and is ready to wear for generations to come.

DIAL:

• Rare silver linear brush dial in near‑mint condition

• Applied Longines winged hourglass logo and crisp “UltraChron” text, a strong sign of originality

• Baton hands with black inserts and applied faceted square hour markers with matching black inserts

CASE:

• Stainless steel case in excellent condition, professionally polished while retaining sharp edges

• 34.0mm width (without crown) / 38.0mm lug‑to‑lug / 9.0mm thickness

• Iconic UltraChron frequency logo on the caseback

• Case Serial: 16036095

MOVEMENT:

• Longines Caliber 6651 – Automatic high‑beat movement

• 28,800 vph / 42hr power reserve / 25 jewels

• Movement serial: 51230797

• Freshly serviced: June 2025

• Accuracy: ~0s/day

BRACELET:

• Original Longines stainless steel bracelet, 18.0mm lug-width

• Original Longines stainless steel folding clasp

• Comes with one original extra link as well

AFTERCARE PACKAGE:

• Comes with a black wooden box + silica gel

• PolyWatch Crystal Polishing kit (for acrylic crystal only)

• 1‑month warranty (non‑user damage)

• Warranty card detailing service history

• Exclusive repair service post‑warranty

• 7‑day return policy for peace of mind

SPECIFICS

Maker: Longines

Model: Ultra-Chron

Year: 1974

Case Material: Stainless Steel

Reference: 8508‑1

Caliber: Cal.6651

Frequency: 28,800vph

Power Reserve: 42hr

Case Serial: 16036095

Movement Serial: 51230797

Diameter: 34.0mm

Lug to lug: 38.0mm

Lug width: 18.0mm

Thickness: 9.0mm

Lume: NIL

Bracelet: Original Longines Full Stainless Steel

Box and papers: NIL

Accuracy: ~0s/day

Movement type: Automatic high‑beat

Crystal: Original Domed Acrylic

Crown: Original Longines‑signed crown

Last service: June 2025

Free tracked shipping via SingPost. Delivery within Singapore in 2–3 working days. International shipping may take 4–16 working days depending on destination.

This is a vintage timepiece and water resistance is not guaranteed. Please avoid contact with water or moisture. Store the watch with dry tissue or silica gel to preserve its condition. We are not liable for water damage post-purchase.