Rolex
GMT-Master 116759 SANR— lug 20mm

The lug width of the Rolex GMT-Master 116759 SANR is 20 millimetres. This measurement represents the distance between the two metal lugs (ears) that protrude from the case and accommodate the strap. To verify, measure with a digital calliper the distance between the lugs: it should read 20mm. This lug width is standard across all modern-generation GMT-Master models.

The optimal strap choice depends on use case and aesthetic preference. Alligator leather (dorsal section with symmetrical grain) is the most elegant and tonally coherent with the instrument-grade character of this model. Shell cordovan develops a crystalline patina with time and acquires a visible history of wear. Calf leather with vegetable tanning is ideal for intensive daily use: durable, develops natural golden patina. For environments with salt exposure or high humidity, rubber or rubber-textile compounds protect the white gold case from corrosion.

To replace the strap, obtain a spring bar tool or consult a qualified horologist. Invert the watch, locate the two lateral elastic pins that support the current strap (one on each side). Use the spring bar tool to gently depress the lateral pin, applying light leverage inward toward the case. The strap detaches when the pin retracts. Repeat for the opposite side. Insert the new strap by aligning the holes with the elastic pins, pressing until the locking click is audible. No proprietary Rolex tools are required for this operation.

Yes, any strap with a 20-millimetre lug width is compatible with the 116759 SANR. Rolex does not exercise proprietary control over lug width specifications. However, precision manufacturing is essential: the strap must be constructed with tolerances no greater than ±0.3mm per side relative to the nominal 20mm measurement, and the lug passage must be geometrically calculated to avoid stressing the pins during wear. Artisanal-quality straps ensure superior longevity and comfort compared to industrial alternatives.

The lifespan of a leather strap depends on frequency of wear, tanning method, and material composition. A high-quality artisanal alligator or shell cordovan strap, worn moderately, lasts 4–6 years before requiring replacement (when leather begins exhibiting structural fatigue or micro-tears at edges). A calf strap subjected to daily intensive stress has comparable longevity (3–5 years). Regular maintenance—air-drying after rainfall, occasional open-air exposure—extends useful life considerably. A rubber strap, being non-organic, has indefinite longevity but is subject to hardening after 8–10 years of continuous solar exposure.