Jaeger-LeCoultre Master

Most Jaeger-LeCoultre Master references take a 20 mm watch strap: 31 of 38. The lug width follows the case size: 39 mm case → 20 mm, 40 mm case → 20 mm, 42 mm case → 21 mm and 43 mm case → 20 mm.

Shop 19 mm Shop 20 mm Shop 21 mm

Jaeger-LeCoultre Master lug width by case size

38 references measured. Updated 2026-10-29.

Case	Lug width	References	Watch strap attachment	For example
39 mm	20 mm	7	—	1422521, 1428121, 1428421
40 mm	20 mm · 19 mm on 2 · 21 mm on 1	16	—	1412530, 1418430, 141848J
42 mm	21 mm · 20 mm on 2	5	—	1562401, 1562421, 1563480
43 mm	20 mm	8	—	1662405, 1662451, 1663314
45 mm	19 mm · 20 mm on 1	2	—	6026412

References that take a different watch strap

1538171: 19 mm, not the 20 mm of most 40 mm cases
1613401: 19 mm, not the 20 mm of most 40 mm cases
1628430: 21 mm, not the 20 mm of most 40 mm cases
1652410: 20 mm, not the 21 mm of most 42 mm cases
52224X8: 20 mm, not the 21 mm of most 42 mm cases
6006405: 20 mm, not the 19 mm of most 45 mm cases

Questions about the Jaeger-LeCoultre Master

Do all Jaeger-LeCoultre Master case sizes take the same watch strap?

No. The lug width changes with the case size: the 39 mm case takes 20 mm, the 40 mm case takes 20 mm, the 42 mm case takes 21 mm and the 43 mm case takes 20 mm. Check your case diameter before you buy.