Jaeger-LeCoultre · Master Control

Strap for Master Control Geographic Pink Gold / Silver / Alligator

Takes 20 mm straps. Verified lug width, the straps that fit this model, and answers to the most common questions.

Lug width20 mm
Case diameter40 mm
ReferenceQ4122520 (aka: 4122520)
FamilyMaster Control
MovementJaeger-LeCoultre caliber 939AA Hours, Minutes, Seconds, World Time, Additional 24 Hour Hand (adjustable), Day / Night Indication | Date | Power Reserve Indicator
CasePink Gold

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 Control Q4122520 (aka: 4122520)

Selected for the 20 mm lug width · workshop selection

All 20 mm straps →

The Master Control Q4122520 (aka: 4122520), seen from the bench

The Master Control World Geographic is powered by the Jaeger-LeCoultre 939AA caliber with functions of hours, minutes, seconds, world time and day/night indicator. The movement includes an adjustable 24-hour hand, date indication and power reserve indicator. The case features 20mm lugs.

Frequently asked questions

What is the lug width of the Jaeger-LeCoultre Master Control Q4122520?

The lug width is 20 millimetres. This measurement is standard for watches with case diameters between 38 and 42 millimetres and ensures harmonious proportions between case and strap. To verify, remove the current strap and measure the distance between the two spring bars protruding from the case lugs.

What type of strap do you recommend for the Master Control Q4122520?

For a rose gold watch of this calibre, we recommend natural leather with vegetable tanning: alligator if budget permits (develops patina over time), or premium calf leather (uniform grain, timeless elegance). Shell cordovan offers rigidity and brilliance but requires constant maintenance. Avoid rubber or silicone: they betray the essence of the timepiece.

How do I change the strap on the Master Control Q4122520?

Use a spring bar tool to gently compress the internal elastic pin and extract it from its seat. The process takes approximately 30 seconds per lug. Position the new strap by inserting one pin into the upper seat first, then apply gentle pressure to seat the second pin. Never force it: the pin should slide smoothly.

Can I use an aftermarket strap compatible with the Q4122520?

Yes, any strap with 20 millimetre lug width is compatible with the Master Control Q4122520. However, we recommend selecting specialised brands that respect the watch's aesthetics: quality leather, precise stitching, noble metal hardware (rose gold, stainless steel, titanium). A mediocre strap diminishes an extraordinary timepiece.

What is the average lifespan of a leather strap for this watch?

A natural leather strap lasts between 2 and 4 years with daily use and regular maintenance. Vegetable-tanned leather extends to 5–7 years if properly cared for (monthly cleaning with damp cloth, annual conditioning with neutral wax). Premium alligator can reach 8 years. Humidity, perspiration, and sunlight exposure accelerate wear.

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