Strap for Big Crown ProPilot GMT Rega Fleet AgustaWestland Da Vinci - HB-ZRR

The Oris ProPilot 01 798 7773 4284 HB-ZRR-Set features a 20 mm lug width. This intermediate standard is typical of professional chronographs and instruments, ensuring balanced torque distribution around the wrist. To verify the exact measurement, place a ruler across the junction between the strap and the case, measuring its total width.

For daily use across professional and casual contexts, a vegetable-tanned calf leather strap offers the optimal balance: immediate softness, natural breathability, and controlled ageing. If you prefer a more robust, low-maintenance solution, a Cordura canvas NATO in grey or black with steel deployante transforms the instrument into a purposeful tool. For discreet elegance, a satin alligator in dark brown elevates the metallic texture of the case without excessive contrast.

Strap replacement on a 20 mm lug width requires a specialised tool: a spring bar tool extractor and a stable work surface. Position the watch face-down, insert the flat screwdriver end of the extractor beneath the spring ring of one bar until tension releases, then extract the bar. Repeat from the opposite side. Replace the worn strap by aligning the new strap's holes with the lug opening, reinsert the springs one at a time ensuring each spring clicks into position. If uncertain, Atelier Casati Milano offers strap change consultation.

A quality leather strap—satin alligator or vegetable-tanned calf—subject to moderate daily wear has a lifespan of 18–24 months before replacement is advisable. Longevity depends on atmospheric exposure, humidity, and frequency of use. A strap rotated among others lasts significantly longer (36–48 months). Atelier Casati Milano recommends timely strap replacement to maintain the aesthetic integrity of your watch.

Yes, a quality aftermarket strap with exactly 20 mm lug width is fully compatible and safe. The critical reference is lug dimension, not brand: a 20 mm Cordovan strap from an Italian artisan manufacturer will pair perfectly with the factory springs of your Oris ProPilot without play or anomalous movement. Atelier Casati Milano supplies made-to-order straps verified for compatibility with your watch's technical specifications.