Strap for La Grande Classique Tonneau 35 Diamond

The lug width of the Longines La Grande Classique L4.789.0.11.6 is 20 mm. It is measured by calculating the distance between the spring bar attachment points located on the case flanks. This uncommon width in the standard strap market requires carefully crafted straps; online you'll find ready-made options or you can request a bespoke strap from Casati Milano.

The best strap depends on your context of use and personal preferences. For a formal approach, a dark brown or black alligator with a stainless steel deployante exudes authority without competing with the watch's sobriety. For daily versatility, a vegetable-tanned calfskin in natural tones offers visible ageing and authentic patina over time. For more casual occasions, a NATO strap in navy blue or charcoal grey maintains elegance and practicality. Your choice should reflect the balance between your personal style and the watch's minimalist character.

The strap is changed using a spring bar tool or a pointed toothpick. Place the watch on a flat surface, locate the spring bars on the case sides, and gently push inward to release the old strap. Once removed, align the new strap (20 mm width) with the lugs and reinsert the spring bars. Do not force it: if the strap doesn't slide in easily, double-check the width. If you're uncertain, consult a professional watchmaker or Casati Milano atelier.

Yes, milanostraps.it offers a selection of 20 mm compatible straps ready for shipment, crafted in alligator, calfskin, NATO canvas, and technical rubber. Each strap is customisable in dimensions, initials, and stitching thread colour. For a fully bespoke experience, the Casati Milano atelier (by appointment) creates made-to-measure straps with personal leather selection, WhatsApp updates during production, and an 18-month warranty.

Longevity depends on the material and use conditions. A high-quality alligator strap, with regular care (gentle cleaning, protection from excessive moisture), can last 3–5 years with daily wear. Vegetable-tanned calfskin, being more porous, typically lasts 2–3 years, though it develops a patina many consider desirable. Factors such as humidity, perspiration, and sunlight exposure influence ageing. Casati Milano guarantees 18 months on its bespoke straps; to extend lifespan, rotate straps regularly and clean them with a damp, dry cloth.