Technical Archive

Longines
Master Collection L2.910.4.77.3— lug 21mm

Longines Master Collection L2.910.4.77.3: 21mm strap. Alligator, box calf, shell cordovan and rubber, cut and stitched in Milano. Choose your leather.

Master Collection 40mm Annual Calendar Stainless Steel / Silver-Diamond / Alligator

Artisanal Note

"This model requires a precise 21mm lug width to preserve the original sartorial balance."

Technical Specifications

Longines L2.910.4.77.3
Lug Width
21 mm

The essential strap measurement.

Browse 21mm straps →
Reference

L2.910.4.77.3

Movement

Longines caliber L897.2 Hours, Minutes, Seconds | Date, Annual Calendar, Month

The Heritage

The Longines Master Collection ref. L2.910.4.77.3 features the automatic caliber L897.2 with hour, minute, second, date and annual calendar with month indication. The case has 21mm lug width. The movement offers a comprehensive time and calendar display through the integrated annual calendar system.

FAQ

What is the lug width of the Longines Master Collection L2.910.4.77.3?

The lug width of the Longines Master Collection L2.910.4.77.3 is 21mm. This measurement is essential for selecting a compatible strap. To verify, simply measure the distance between the two lugs (pins) that secure the strap to the case. Any strap with a 21mm lug width will fit perfectly on this model.

What is the best strap for the Longines Master Collection L2.910.4.77.3?

The best strap for the L2.910.4.77.3 depends on intended use and personal preference. For a classical aesthetic, we recommend alligator leather with vegetable tanning, which creates a fluid visual transition with the brushed steel case. Hermès calf leather offers a uniform, elegant surface, while natural rubber provides sporty practicality whilst maintaining the watch's understated design. On milanostraps.it, you'll find all compatible 21mm straps, customisable in colour, length, and details.

How do I change the strap on the Longines Master Collection L2.910.4.77.3?

To change the strap on the L2.910.4.77.3, use a dedicated spring bar removal tool or gentle tweezers. First, place the watch on a soft surface to prevent scratches. Gently push the metal pin connecting the strap to the case from one side to the other. Once the pin is removed, the old strap will detach. Align the new strap's holes with the lugs and reinsert the pin. For safety, consider having the operation performed by a specialist watchmaker.

Can the strap on the Longines Master Collection L2.910.4.77.3 be replaced with an aftermarket model?

Yes, the strap on the L2.910.4.77.3 can be entirely replaced with a quality aftermarket strap, provided the lug width is exactly 21mm. Custom-made artisanal straps allow full personalisation regarding material (alligator, calf, shell cordovan), colour, length, and finishes. On milanostraps.it, you can select from several ready-made options or commission a bespoke strap through the Casati Milano atelier, which includes an 18-month warranty.

How long does a leather strap last on the Longines Master Collection L2.910.4.77.3?

A leather strap's lifespan depends on material, frequency of use, and maintenance. An alligator strap with vegetable tanning typically lasts 3 to 5 years with daily wear, developing an elegant patina over time. Calf leather tends to last slightly less (2 to 4 years), whilst shell cordovan is renowned for extraordinary durability, easily exceeding 7 to 10 years. Regular maintenance—gentle cleaning and annual conditioning—significantly extends service life. Artisanal straps from milanostraps.it include an 18-month warranty against manufacturing defects.