Strap for Seamaster Aqua Terra 150M Master Chronometer 34 Sedna Gold / Diamond / Snow Ruby / Alligator

The lug width of the 220.58.34.20.99.001 model is 16mm. This design constraint is specific to the 34mm case in Sedna Gold and determines compatibility with aftermarket straps. Measurement is taken internally, from edge to edge of the upper lug, using a digital caliper or precision ruler.

To enhance the Sedna Gold, we recommend dark brown or black alligator for maximum formality, burgundy shell cordovan for elegance with natural patina, or grey calf for modernity. For versatility, the blue/beige NATO allows quick alternation while maintaining 34mm case proportions. Choice depends on use: event (alligator), collection piece (shell), alternation (NATO).

Strap replacement requires a spring bar remover tool inserted under the lug to compress the lateral springs. Position yourself in good lighting, remove the upper lug first, then the lower one. Insert the new strap (always 16mm width) under the lugs, verifying that the springs click correctly. If you prefer to avoid the risk of scratches, the Casati Milano atelier offers a strap change service by appointment.

All straps with 16mm lug width are compatible with this model. On milanostraps.it you will find a curated selection of alligator, shell cordovan, calf, NATO and rubber, customizable in length, color and thread color. The 16mm width is the unique constraint; length is adjusted to your wrist during customization.

A quality leather strap (alligator, shell cordovan, calf) lasts an average of 3-5 years with daily use, extendable to 7-10 years with maintenance (cleaning, conditioning, drying). Shell cordovan is the most durable thanks to fiber density. Tropic rubber lasts 5-8 years. Fabric NATO persists beyond 10 years. Casati Milano warranty covers all straps for 18 months.