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Sistem 51 SUTB404— lug 16mm

The SUTB404 features a 16-millimetre lug width. This measurement is specific to this model and must be respected when selecting a replacement strap. To measure the lugs, position the ruler from one spring bar to the other internally, perpendicular to the line connecting the lugs of the case.

The ideal strap depends on personal style. To emphasise the transparent case design, we recommend fine-grain alligator. For a classical approach, vegetable-tanned calf leather develops a beautiful patina over years. A NATO strap in cordura maintains the radical aesthetic coherence of the design. Vulcanised rubber underscores the functional pragmatism of the watch.

The SUTB404 uses a spring bar fastening system. To change the strap, you must remove the spring bars from the case lugs using a dedicated tool or thin screwdriver. Insert the new strap by seating the passant rings onto the spring bars, then re-insert the bars. This operation requires care to avoid damaging the plastic case.

Yes, you can use replacement straps provided they respect the 16-millimetre lug width. It is important to verify that the spring bars are compatible with the plastic case. We recommend straps specifically manufactured for 16mm lugs to ensure precise fit and avoid structural tension on the case.

A quality leather strap on a daily-worn watch maintains structural functionality for 3 to 5 years. Durability varies depending on the material (calf, alligator, shell cordovan react differently to moisture) and the environment of use. Vegetable-tanned leather develops patina and character over time, whilst rubber remains unchanged for longer periods.