Longines · Master Collection

Strap for Master Collection 42 Moonphase Stainless Steel / Blue - Diamond

Takes 21 mm straps. Verified lug width, the straps that fit this model, and answers to the most common questions.

Lug width21 mm
Case diameter42 mm
ReferenceL2.919.4.97.
FamilyMaster Collection
MovementLongines caliber L899.2 hours, minutes, small seconds | date | moonphase
Year2021
CaseStainless Steel

Spring bar

Swiss Standard universal spring bars

The right category for this model · 316L steel, all lug widths 13–26 mm

Straps for the Master Collection L2.919.4.97.

Selected for the 21 mm lug width · workshop selection

All 21 mm straps →

The Master Collection L2.919.4.97., seen from the bench

The Longines Master Collection features the caliber L899.2 with functions of hours, minutes, small seconds, date and moon phases. The case has 21mm lugs. The movement offers moon phase indication in addition to the basic time functions.

Frequently asked questions

What is the lug width of the Longines Master Collection L2.919.4.97.?

The lug width of the L2.919.4.97. is precisely 21 mm. This measurement is determined by the 42 mm case geometry and remains constant across all examples. To verify, position a caliper on the spring bar holes and measure the internal distance.

Which strap is most recommended for the Master Collection L2.919.4.97.?

A crocodile leather strap represents the most coherent choice for this dress-watch character. Crocodile in cognac brown or black offers understated elegance and develops a natural patina over time. Shell cordovan and vegetable-tanned calf leather are excellent alternatives for those seeking more personal materials.

How do you change the strap on the Longines Master Collection L2.919.4.97.?

The strap is secured to the case via removable spring bars. To change it: (1) position the watch on a soft cushion with dial facing down; (2) use a thin lever tool to press the internal spring mechanism of the upper bar whilst lifting the pin; (3) remove the pin completely; (4) repeat for the lower bar; (5) position the new strap and reinsert the bars in reverse order. If inexperienced, consult a professional to avoid case damage.

Is a 21mm aftermarket strap compatible with the Longines L2.919.4.97.?

Yes, any strap with a 21 mm lug width is physically compatible. However, the strap must be constructed to fit perfectly with the case geometry without creating visible gaps between strap and case profile. Bespoke artisanal straps guarantee this aesthetic compatibility.

How long does a leather strap last on this model?

A quality leather strap (crocodile, calf, shell cordovan) typically lasts 3–5 years with standard daily wear. Durability depends on: wearing frequency, moisture exposure, perspiration and maintenance. Vegetable-tanned leather ages more elegantly but requires occasional light care. An 18-month warranty is standard for bespoke artisanal straps.

The next step

The right strap isn't chosen. It is built, together.

From the atelier appointment to delivery, every step is made for those who know that things done well take time. Rare leathers, one piece at a time, eighteen months of warranty.

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Casati Milano · Via XX Settembre 15, Milan · by appointment only