Strap for Divers Sixty-Five 42 Stainless Steel / Blue / NATO

The lug width of the Oris Divers 65 01 733 7720 4055-07 5 21 28FC is 21mm. This unusual specification maintains fidelity to the 1960s prototype. To verify compatibility, measure the internal distance between the two spring bar holes with a digital calliper, ensuring that the washer thickness is between 1.4-1.6mm.

For this diver, we recommend genuine alligator in vegetable tanning for vintage elegance, or vegetable-tanned calf for the compromise between formality and durability. For humid environments or actual diving, FKM rubber guarantees complete waterproofing. NATO straps in cotton-polyester offer critical change speed in maritime applications.

Use a spring bar tool to extract the pins from the watch case lugs, working from one end at a time. Insert the new strap by aligning the holes with the pins, pressing until you hear a distinct click confirming the anchorage. Avoid forcing: insufficient space indicates size incompatibility.

No. A 20mm or 22mm lug width will not fit the 21mm lugs of the Divers 65 without forcing, which would compromise the integrity of the case or buckle. Request straps specifically sized for 21mm from specialised artisans such as Casati Milano.

A quality leather strap (alligator or vegetable-tanned calf) requires replacement after 4-7 years of daily use, provided regular maintenance: rinsing in fresh water after sweat exposure, air drying, and occasional application of leather conditioner. NATO or rubber straps require less maintenance but have similar longevity if subjected to prolonged salt water exposure.