Strap for Spacematic Pilot Professional PVD

The lug width of the Fortis Cosmonaut 623.18.71 is 20mm. This specific measurement was selected by Fortis to maintain optimal proportions on the 40mm case. To verify compatibility, measure between the inner shoulders of the lugs using a digital calliper, excluding the mounting gap. Inaccurate measurement risks receiving incompatible strap orders.

For formal wear, alligator leather in vegetable tanning offers sophistication and longevity. For tactical and aquatic activity, treated rubber ensures grip and humidity resistance. For historical authenticity, military cotton NATO reflects original cosmonaut heritage. Smoked calf provides a balanced compromise between cost, initial suppleness, and visible ageing. Choice depends on intended primary use context.

Use a dedicated spring bar tool. Position the watch on a stable surface, insert the bifid tip of the tool into the lateral access hole of the lug, apply gentle pressure to compress the return spring, then extract the pin from the lug seat. Repeat on the opposite lug. For new strap installation, reverse the procedure: align the holes, insert one end of the spring bar first (typically the buckle side), compress the spring, and secure fully. Avoid excessive pressure that could damage the inner lug shoulders.

Yes, provided the lug width is exactly 20mm and thickness does not exceed 4.5mm (physical clearance limit between lug and case). Quality aftermarket straps use the same universal spring bar attachment systems as OEM straps. However, we recommend verifying construction specifications with the supplier before purchase. Some vintage or specialised straps (such as shell cordovan) may require custom spring bars if thickness exceeds standard.

A quality leather strap (alligator, cordovan, premium calf) has an average lifespan of 5–7 years with moderate daily wear. Longevity depends on three factors: frequency of wear, ambient humidity, and maintenance. Vegetable-tanned leathers age better than chrome-tanned, developing appealing patina. A rubber strap, though more water-resistant, degrades after 8–10 years due to elastomer molecule oxidation. Store straps in dry spaces, avoid prolonged contact with salt sweat, and occasionally apply natural oils (such as neatsfoot) to maintain fibre flexibility.