Strap for Speedmaster Professional Missions Apollo 8

The lug width of the Speedmaster Moonwatch 3597.12.00 is 20mm. This dimension is standard for the Professional model and is determined by the internal distance between the two lugs of the case. It is essential to verify this measurement before purchasing an aftermarket strap, as 20mm is not universal: the Moonwatch is not compatible with 18mm or 22mm straps.

The choice depends on personal style and intended use. Alligator is the classic choice for formal elegance and visual legibility of the case. Vegetable-tanned calf offers an authentic patina that evolves over time. Shell cordovan is extraordinary for resistance and density. Fabric NATO is historically correct (the Moonwatch was delivered with textile in NASA kits). Modern rubber is the pragmatic solution for humid environments and sports use.

Changing the strap on the Speedmaster 3597.12.00 requires a tiny flathead screwdriver or a dedicated tool. Locate the two screws that secure the lugs to the case (one on each side). Unscrew gently without forcing, and the strap will detach. Insert the new 20mm strap by sliding the lugs into their seats, then tighten the screws with steady and moderate pressure—not excessive, as this could damage the brushed steel.

Yes. Aftermarket straps in 20mm are completely compatible with the Moonwatch, provided they respect this lug width. Many collectors prefer artisanal leather straps over the original integrated steel bracelet: the chromatic versatility and quality of materials offer a deeper relationship with the instrument. Specialized brands such as milanostraps.it offer custom straps with certified quality leathers.

The durability of a leather strap depends on the material and usage. Vegetable-tanned calf can last 3-5 years with daily wear without excessive sun exposure. Alligator, thanks to fiber density, can reach 5-7 years. Shell cordovan can exceed 10 years. Modern rubber, by contrast, degrades faster (2-3 years) due to UV and chlorine exposure. Casati Milano offers an 18-month warranty on artisanal straps, and vegetable-tanned calf develops a patina with elegance, so visual degradation is often perceived as acquired character rather than deterioration.