Technical Archive

Longines
Conquest L3.257.4.57.6 (aka: L32574576)— lug 15mm

Longines Conquest L3.257.4.57.6 (aka: L32574576): 15mm strap. Alligator, box calf, shell cordovan and rubber, cut and stitched in Milano. Choose your leather.

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

L3.257.4.57.6 (aka: L32574576)

Movement

Longines caliber L250 Hours, Minutes, Seconds | Date

The Heritage

The Longines Conquest L3.257.4.57.6 is a women's timepiece featuring a 29.5mm stainless steel case with a matte black ceramic bezel. It houses the Longines caliber L250 automatic movement with hours, minutes, seconds, and date display. The sapphire crystal protects the dial while the ceramic and steel case offers corrosion resistance and daily wear durability at 30 meters water resistance. The 15mm lug width is specific to this model and requires a correspondingly sized strap for proper fit.

FAQ

What is the lug width of the Longines Conquest L3.257.4.57.6?

The lug width is 15mm. This dimension is specific to the L3.257.4.57.6 model (alternative reference L32574576) and reflects the proportions of the 29.5mm case diameter. Measure the internal distance between the two lugs with a millimetre calliper to confirm before ordering an aftermarket strap.

Which type of strap is most suitable for the Longines Conquest L3.257.4.57.6?

We recommend an alligator or vegetable-tanned calf strap to enhance the elegance of the ceramic and steel case. For a sportier approach, a rubber or fabric NATO strap maintains the aviatory heritage of the Conquest. Your choice depends on daily wear and personal colour preferences.

How do I change the strap on my Longines Conquest L3.257.4.57.6?

The strap is changed by removing the metal lugs at the ends of the case. Use a spring bar tool (a small metal device) to release the spring mechanism of the lugs, then remove the old strap and insert the new one. If you are unsure, consult a watchmaker or the Casati Milano service.

Can I use an aftermarket strap compatible with my Longines Conquest L3.257.4.57.6?

Yes, provided the strap is specifically constructed for the 15mm lug width. On milanostraps.it you will find a selection of 15mm straps ready for shipping, made from premium materials such as alligator, vegetable-tanned calf and shell cordovan. All are compatible with your timepiece.

How long does a leather strap last on the Longines Conquest L3.257.4.57.6?

Durability depends on the material and level of use. A quality handcrafted vegetable-tanned calf strap lasts 5-7 years with moderate daily wear. Alligator and shell cordovan, being denser hides, can last 8-10 years. The natural patina that develops over time is an added value, making each strap unique and personalised. Casati Milano offers an 18-month warranty.