Strap for Harmony Split-Seconds Ultra Thin

The Vacheron Constantin Harmony 5400S/000P-B057 has a lug width of 22 mm, measured internally between the lugs at the point where the spring bar sits. The tonneau-shaped platinum 950 case features slightly tapered lugs towards the tips: it is essential to measure the interlugs precisely with a digital calliper to ensure the strap fits flush with no visible gap.

For a platinum 950 tonneau case, Mississippiensis alligator in vegetable-tanned leather with a centred, symmetrical grain is the most coherent choice for the Haute Horlogerie register of this piece. Alternatively, lacquered black box-calf or wax-polished shell cordovan in midnight blue or deep burgundy provide highly refined chromatic pairings. A deployant clasp in platinum or brushed steel completes the aesthetic consistency of the ensemble.

Strap replacement is carried out via the spring bars housed in the lugs of the tonneau case. It is strongly recommended to use a lever-type spring bar tool with a Teflon or nylon tip to avoid scratching the platinum, which is a relatively soft metal susceptible to marking. Given the value of the case, the operation is best performed by a qualified watchmaker or directly at the Casati Milano atelier.

Yes. Aftermarket straps of 22 mm with a straight or slightly tapered end are fully compatible with the Vacheron Constantin Harmony 5400S/000P-B057. Milano Straps offers handcrafted straps in alligator, calfskin, shell cordovan and technical rubber made to measure at the Casati Milano atelier, with buckles and deployant clasps available in steel or precious metal on request.

The lifespan of a leather strap depends on the material, frequency of wear and level of care. A quality vegetable-tanned alligator strap, worn in rotation and kept away from water and perspiration, will maintain its structural integrity and finish for 3 to 5 years. Shell cordovan, owing to the density of its fibre, tends to last longer and develops a distinctive patina over time. All Milano Straps straps carry an 18-month warranty against manufacturing defects.