Jaeger-LeCoultre · Master Ultra Thin
Strap for Master Ultra Thin Date Stainless Steel / Silver / Alligator
Takes 20 mm straps. Verified lug width, the straps that fit this model, and answers to the most common questions.
Lug width
20mm
Lug width20 mm
Case diameter39 mm
Reference1238420 (aka: Q1238420)
FamilyMaster Ultra Thin
MovementJaeger-LeCoultre caliber 899/1
Hours, Minutes, Seconds | Date
CaseStainless Steel
Straps for the Master Ultra Thin 1238420 (aka: Q1238420)
Selected for the 20 mm lug width · workshop selection
Black Alligator Strap with Light Blue Edges€210
Black Alligator Strap with White Edges€210
Millenium Cognac Alligator Strap€270
Matte Blue Alligator Strap€270
Green Rubberized Alligator Strap with Ecru Tribal Stitching€185
The Master Ultra Thin 1238420 (aka: Q1238420), seen from the bench
The Jaeger-LeCoultre Master Ultra Thin Date 1238420 (Q1238420) belongs to a family that redefined ultra-thin wristwatch standards since its introduction. The stainless steel version features a 39mm case with the distinctive thin profile enabled by the manual-wound Jaeger-LeCoultre 899/1 caliber, which integrates hours, minutes, seconds, and date. The 20mm lug width is native to this model and requires a compatible strap to maintain aesthetic proportions; alligator leather with horizontal grain is the classic choice.
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.
Request an appointment →Casati Milano · Via XX Settembre 15, Milan · by appointment only