Longines Conquest

Most Longines Conquest references take a 21 mm watch strap: 82 of 243. The lug width follows the case size: 30 mm case → 15 mm, 34 mm case → 17 mm, 39 mm case → 19 mm and 41 mm case → 21 mm.

Shop 20 mm Shop 21 mm Shop 22 mm

Longines Conquest lug width by case size

243 references measured. Updated 2026-10-29.

Case	Lug width	References	Watch strap attachment	For example
25 mm	12 mm	10	—	L3.157.4.57.2, L3.157.4.57.6, L3.157.4.87.2
30 mm	15 mm	42	—	L3.180.0.57.6, L3.180.0.87.6, L3.257.4.16.6
34 mm	17 mm · 20 mm on 2	35	—	3.430.4.90.9, L3.377.3.87.7, L3.377.4.16.6
35 mm	17 mm	14	—	L3.279.0.57.6, L3.279.0.87.6, L3.279.4.56.3
36 mm	17 mm	8	—	L3.377.4.57.6, L3.378.4.16.6, L3.378.4.57.6
38 mm	19 mm	8	—	L3.720.4.02.6, L3.720.4.02.9, L3.720.4.52.6
39 mm	19 mm	19	—	L3.655.4.56.0, L3.655.4.56.2, L3.655.4.56.6
41 mm	21 mm · 20 mm on 3	82	—	L2.743.4.56.6, L2.743.4.76.6, L2.744.4.06.7
42 mm	22 mm	11	—	L3.835.4.02.6, L3.835.4.02.9, L3.835.4.32.6
43 mm	22 mm	1	—	L3.760.4.56.6
not recorded	22 mm · 15 mm on 3 · 21 mm on 3 · 17 mm on 1 · 20 mm on 1	13	—	L3-760-4-96-0, L3.697.4.06.6, L3.697.4.56.6

References that take a different watch strap

L3.400.0.57.6: 20 mm, not the 17 mm of most 34 mm cases
L3.400.0.87.6: 20 mm, not the 17 mm of most 34 mm cases
L3.687.4.56.6: 20 mm, not the 21 mm of most 41 mm cases
L3.687.4.76.6: 20 mm, not the 21 mm of most 41 mm cases
L3.687.4.99.6: 20 mm, not the 21 mm of most 41 mm cases
L3-377-4-97-6: 17 mm
L3-759-4-76-6: 21 mm
L3-788-4-06-6: 21 mm
L3-788-4-96-6: 21 mm
L3.277.4.57.6: 15 mm
L3.299.0.57.7: 20 mm
L3.300.0.57.6: 15 mm
L3.300.0.87.6: 15 mm

Questions about the Longines Conquest

Do all Longines Conquest case sizes take the same watch strap?

No. The lug width changes with the case size: the 30 mm case takes 15 mm, the 34 mm case takes 17 mm, the 35 mm case takes 17 mm, the 39 mm case takes 19 mm and the 41 mm case takes 21 mm. Check your case diameter before you buy.