Strap for Prim Sport 105

The Prim Sport Ref. 105 features 20mm lugs (lug width). This measurement is crucial when selecting an aftermarket strap: the spring bars must be positioned perpendicularly to the case to ensure a fit without play and proper distribution across the lugs. To verify strap compatibility, measure the distance between the spring bars using a digital calliper, ensuring the width corresponds precisely to 20mm.

Selection depends on intended use and aesthetic preferences. For formal-sport wear, we recommend a vegetable-tanned calf leather strap in cognac or dark brown: the natural patina developing over time enhances the strap's visual value. For a more sophisticated pairing, alligator leather in black or dark brown confers authority and refinement. For those preferring practicality and durability, a ballistic nylon NATO strap remains the most reliable solution for daily operations.

Strap replacement requires removal of the spring bars connecting the strap to the case lugs. Position the watch on a flat surface, then use a spring bar tool (precision instrument) to apply gentle pressure on the spring bar towards the inside of the case, releasing the end from the lug. Once the spring bar is removed, slide the old strap away from the case. The new 20mm strap is inserted by aligning the holes with the spring bars; subsequently, reinsert the spring bars whilst applying controlled pressure until you feel the locking click. Verify proper tension by gently pulling the strap.

The Prim Sport 105 accepts any strap with a 20mm lug width. Compatibility is assured across a vast range of materials: vegetable-tanned calf leather, alligator, shell cordovan, NATO fabrics, synthetic rubber (FKM). Milano Straps offers a curated selection of 20mm straps ready for dispatch, customisable according to aesthetic and constructive preferences. It is important to verify that the chosen strap has adequate thickness (generally between 3.5mm and 4.5mm) to avoid fitting issues.

Leather strap longevity depends on leather quality and maintenance level. A vegetable-tanned calf leather strap of good quality offers an average lifespan of 3-5 years with moderate daily use. More noble leathers, such as alligator or shell cordovan, can exceed 7-10 years if subjected to periodic maintenance (gentle cleaning with specific detergents, conditioning with natural creams). The most delicate wear area is the bending point at the buckle height: reduced watch movement across wrists of varying circumference helps extend strap life.