Technical Archive

Longines
Master Collection L2.257.4.97.0— lug 15mm

Longines Master Collection L2.257.4.97.0: 15mm strap. Alligator, box calf, shell cordovan and rubber, cut and stitched in Milano. Choose your leather.

Master Collection Date 29 Stainless Steel / Blue - Diamond

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

L2.257.4.97.0

Movement

Longines caliber L592.2 Hours, Minutes, Seconds | Date | Chronometer

The Heritage

The Longines Master Collection L2.257.4.97.0 is a 29mm stainless steel dress watch featuring a refined case, a legible blue dial with applied indices, and a 15mm lug width. Powered by the Longines L592.2 automatic movement certified chronometer by COSC standards, it ensures precision within ±4 seconds per day. The 316L stainless steel case offers water resistance to 30 meters and houses a sapphire crystal with date window, embodying the contemporary evolution of Longines' watchmaking heritage since 1832.

FAQ

What is the lug width of the Longines Master Collection L2.257.4.97.0?

The lug width of the Longines Master Collection L2.257.4.97.0 is 15 millimetres. This non-standard measurement is specific to the Master Collection women's models and corresponds to the proportional ratio between the 29mm case and the average feminine wrist size. To verify it, position a digital calliper from the case lugs to the opposite extremity of the lug.

Which strap is recommended for the Longines Master Collection L2.257.4.97.0?

Alligator represents the most natural choice for this dress watch, particularly in cognac, tobacco, or black finishes. Vegetable-tanned calf leather with irregular grain develops a patina over time, whilst smooth calf offers formal character. For daily versatility, silk NATO straps and vulcanised rubber retain the aesthetic balance of the 29mm case.

How do you change the strap on the Longines L2.257.4.97.0?

The strap is replaced using a removable spring bar tool or through a qualified watchmaker. Insert the tool's tip into the lug hole, gently push downward until the first strap end is released, then repeat on the other side. Insert the new strap by snapping the spring bars back into place. Consult a professional if uncertain of the procedure.

Is an aftermarket strap compatible with the Longines Master Collection L2.257.4.97.0?

Yes, provided the strap is specifically manufactured for the 15mm lug width, particularly for this model or the Master Collection women's line. Always verify the retailer's technical specifications and ensure the strap ends are compatible with your case lugs. Milano Straps offers a dedicated collection of 15mm straps ready for dispatch.

How long does a leather strap last on the Longines Master Collection?

A quality leather strap, in vegetable tanning or alligator, typically lasts 3–5 years with moderate daily use. Longevity depends on ambient humidity, frequency of wear, leather quality, and maintenance. Smooth calf straps tend to wear earlier, whilst alligator and cordovan offer superior durability. The Casati Milano atelier provides an 18-month warranty on bespoke straps.