Longines · Conquest

Strap for Conquest 38 Stainless Steel / Black / Rubber

Takes 19 mm straps. Verified lug width, the straps that fit this model, and answers to the most common questions.

Lug width19 mm
Case diameter38 mm
ReferenceL3.720.4.52.9
FamilyConquest
MovementLongines caliber L888.5 hours, minutes, seconds | date | chronometer
Year2025
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 Conquest L3.720.4.52.9

Selected for the 19 mm lug width

All 19 mm straps →

The Conquest L3.720.4.52.9, seen from the bench

The Longines Conquest L3.720.4.52.9 is a 38 mm stainless steel sports watch from the Conquest family, launched in the 1950s for mountaineers and professionals. It features a quartz caliber L888.5 movement certified chronometer with chronograph function, hour, minute, second and date display, ensuring ±10 seconds per month precision. The case offers corrosion resistance and natural patina development, while the screw-down crown provides water resistance for light water sports. The 19 mm lug width is a key specification requiring dedicated strap selection for proper fit and aesthetics.

Frequently asked questions

What is the exact lug width of the Longines Conquest L3.720.4.52.9?

The lug width of the Longines Conquest L3.720.4.52.9 is 19 millimetres. This measurement is specific to this model and requires dedicated straps, as standard aftermarket options rarely reach this dimension. To verify the measurement, use a digital calliper, measuring the interior distance between the two lugs on the case.

What is the best strap for the Longines Conquest L3.720.4.52.9?

The optimal strap depends on intended use. For formal elegance, we recommend black alligator or shell cordovan with vegetable tanning; for daily versatility, pearl grey or black calf leather in vegetable tanning; for sporting activities, NATO straps or natural vulcanised rubber. Vegetable-tanned leather guarantees durability exceeding 15 years of continuous wear.

How do I change the strap on the Longines Conquest L3.720.4.52.9?

To change the strap, use a spring bar tool (specialised tool with bifid tip). Insert the tip into the spring bar holes, apply gentle upward pressure to release the bar from its seat, then remove the previous strap. Insert the new strap by aligning the holes with the lugs and press the spring bar until it clicks into place. Verify the bar is fully seated.

Does the Longines Conquest L3.720.4.52.9 accept compatible 19mm aftermarket straps?

Yes, the Longines Conquest L3.720.4.52.9 is fully compatible with high-quality 19mm aftermarket straps. Specialist retailers such as Milano Straps offer personalised straps in leather, alligator, shell cordovan and rubber, all calibrated for this specific lug width.

What is the expected lifespan of a leather strap for the Longines Conquest L3.720.4.52.9?

A high-quality natural leather strap, subjected to vegetable tanning, has an estimated lifespan of 15-20 years with daily wear. Longevity depends on frequency of use, exposure to moisture and ambient relative humidity. Regular maintenance (gentle cleaning and annual conditioning with specialised balms) extends strap life.

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