Technical Archive

Longines
Flagship L4.374.3.78.7— lug 15mm

Longines Flagship L4.374.3.78.7: 15mm strap. Alligator, box calf, shell cordovan and rubber, cut and stitched in Milano. Choose your leather.

Flagship 30 Stainless Steel - Pink Gold / Grey / Bracelet

Artisanal Note

"This model requires a precise 15mm lug width to preserve the original sartorial balance."

Lug Width

15 mm

The essential strap measurement.

Browse 15mm straps →

Reference

L4.374.3.78.7

Movement

Longines caliber L592.5 Hours, Minutes, Seconds | Date | Chronometer

The Heritage

The Flagship represents one of Longines' historic collections, characterized by classic and elegant lines. It features the L592.5 caliber with hour, minute, second, date functions and chronometer certification. The case has 15mm lugs and reference L4.374.3.78.7.

FAQ

What is the lug width of the Longines Flagship L4.374.3.78.7?

The Longines Flagship L4.374.3.78.7 features a 15mm lug width, a non-standard measurement requiring purpose-built straps. To verify, measure from the centre of one lug to the other using a ruler or calliper.

What is the best strap for the Longines Flagship L4.374.3.78.7?

For this 30mm dress watch, we recommend vegetable-tanned alligator with fine grain, or shell cordovan for superior longevity and accelerated patina. Both enhance the satinised silver dial of the Flagship without compromise.

How do I change the strap on the Longines Flagship L4.374.3.78.7?

Use a spring bar removal tool (pressing the small metal release button) whilst supporting the strap. Insert the new strap, aligning it with the 15mm lugs. If uncertain, consult a trusted watchmaker to prevent damage.

Can I use an aftermarket strap on the Longines Flagship L4.374.3.78.7?

Yes, provided the lug width is precisely 15mm. Straps of 14mm or 16mm will cause visual and functional misalignment. Milano Straps offers artisanal straps compatible with this model, customisable in leather and colour.

How long does a leather strap last on the Longines Flagship?

An artisanal strap in alligator or shell cordovan, with ordinary care, maintains functionality and aesthetics for 3–5 years. Natural patina improves over time. Shorter lifespan (2–3 years) for Taurillon calf. Controlled ageing is a quality characteristic, not a defect.