Strap for Flagship 40 Stainless Steel / Black / Bracelet

The lug width of the Longines Flagship L4.984.4.59.6 is precisely 21 millimetres. This measurement must be respected exactly to avoid structural play or mechanical pressure on the case lugs. Correct measurement: position a ruler from the inner bottom of one lug to the other, between the strap attachment points.

For the Flagship, the following are recommended: African alligator for formal contexts (noble grain with visible patina evolution), vegetable-tanned calf for aesthetic pairing with satin-finished steel, high-density rubber for robust daily use. Choice depends on your usage context and personal aesthetic sensitivity. Avoid low-quality synthetics that undermine the watch's artisanal vocation.

The strap is changed using a removable spring bar tool: position the thin end under the internal spring of the lug, apply gentle pressure to compress the spring, remove the lug from the case flange and remove the old strap. Insert the new strap by aligning the lug holes, compress the new lug spring and position it in the flange. The operation requires care to avoid scratching the satin-finished case.

Yes, provided they respect the certified 21-millimetre lug width. Artisanal aftermarket straps from specialist retailers often offer superior construction quality compared to standard OEM straps. Choose artisans who understand your watch's proportions and use certified leathers (African alligator, shell cordovan, naturally-dyed calf).

A premium-quality leather strap (African alligator, calf, shell cordovan) used daily reaches 18-24 months of intensive wear before showing excessive structural deterioration. Lifespan depends on wearing frequency, direct sun exposure, humidity and maintenance. Artisanal straps with vegetable tanning develop visible patina after 6 months and improve aesthetically over time, whilst synthetics maintain unchanged appearance until sudden failure.