Strap for OutDoor 39 Protect Stainless Steel / Lume / Bracelet

The lug width is precisely 20mm, measured as the distance between the two spring bar pins. Verify by placing a ruler from the first to the second pin—it must correspond exactly to 20mm. Do not confuse this dimension with the thickness of the spring bar or the internal width of the case.

The choice depends on intended use: a NATO in nylon or cotton emphasises the instrumental character and guarantees humidity resistance; a vegetable-tanned leather offers natural patina and vintage aesthetics; an FKM rubber is essential for aquatic environments. The UA8239B-A1.1-H expresses itself best with robust materials that respect the outdoor vocation of the movement.

The UA8239B-A1.1-H uses a spring bar mechanism. Remove the old strap by gently pushing the spring bar inward with a spring bar tool, sliding it laterally. Insert the new spring bar into the first pin, then press the strap toward the second pin until the bar locks into position.

Yes, provided the lug width is exactly 20mm. Verify compatibility before purchase by measuring the distance between the spring bar pins: any deviation from 20mm will result in improper installation. Many artisanal straps are available in this rare size.

A quality leather strap, subjected to moderate daily use, typically lasts 2-4 years before requiring replacement. Longevity depends on humidity exposure, frequency of use, and maintenance. Vegetable-tanned leather tends to outlast chrome-tanned varieties, developing pleasant patina rather than degrading suddenly.