Strap for Tangente 35 Four Seasons Spring / Enju

The lug width of the 139.S20 is 18mm. This measurement refers to the internal distance between the spring bars (the attachment pins) that connect the case to the strap. All straps compatible with this width will fit perfectly in the case lugs, ensuring correct geometric interface and a seamless line with no lateral play.

The ideal strap depends on usage and aesthetic preference. For formal wear, we recommend soft alligator with fine grain or vegetable-tanned calf leather with aged patina: these materials enhance the Bauhaus austerity of the watch. For versatile everyday use, a NATO strap in cordura with sage grey or deep blue tones introduces modernity whilst preserving aesthetic coherence. FKM rubber straps with satin finish are ideal for professional environments where leather would be inappropriate.

Strap replacement is a straightforward operation. Using a spring bar tool (or equivalent instrument), apply gentle pressure to the rear of the spring pin, releasing the bar from the case lug holes. Once the pin is extracted on both sides, the old strap slides out easily. To install the new strap, align the bar on the lug and compress the pin into position until you feel a gentle click. Ensure the pin is fully seated and the strap is aligned symmetrically.

Yes, any strap with an 18mm lug width is compatible with the 139.S20. High-quality aftermarket straps, crafted from excellent leather (alligator, vegetable-tanned calf, shell cordovan) or technical materials (NATO, rubber), fit perfectly in the case lugs and allow you to personalise the watch's aesthetics completely whilst maintaining the proportionality of the original design.

Durability depends on material quality, daily wear and maintenance. A high-quality vegetable-tanned calf or alligator strap, worn regularly, maintains structural and aesthetic integrity for 3–5 years. Factors such as humidity, frequency of wear and protection from impacts accelerate ageing. With proper maintenance (periodic cleaning with a soft damp cloth, occasional application of natural balm), the leather develops a fascinating patina that enriches the watch's aesthetic value over time.