Strap for Prospex Diver 1970 Stainless Steel / Blue / Bracelet

The lug width of the Seiko Prospex Divers SPB183 is 20 millimetres. This measurement is the standard for mid-sized dive watches and ensures harmonious proportions on most wrists. You can verify this measurement by inserting a digital calliper between the lugs (the metal pins connecting the strap to the case), keeping the calliper parallel to the dial.

For the Prospex Divers SPB183, we recommend three options: an alligator strap with vegetable tanning for formal use (natural leather enhances the blue dial), a grey-taupe calf leather strap for elegant daily wear, or an FKM rubber strap for regular diving activities. Your choice depends on your lifestyle and intended usage. All these materials are available in 20mm lug width.

Changing the strap on a Prospex Divers is a relatively straightforward operation: place the watch on a soft surface, locate the two metal pins passing through the case (one on each side), use a dedicated tool or fine-bladed knife to gently push the pin from one side, allowing the strap to separate from the case. Repeat for the other side. Insert the new strap by aligning the holes with the lugs, then reinsert the pins. If unsure, contact the Casati Milano atelier for professional strap changing.

The SPB183 is compatible with any artisanal strap with a 20mm lug width. On MilanoStraps you will find a curated selection of natural leather straps (alligator, calf, shell cordovan), textile straps (NATO), and technical rubber straps. All our 20mm products have been tested for compatibility with the Prospex Divers and maintain the aesthetic integrity of the model.

The lifespan of a natural leather strap depends on the tanning method used and the intensity of wear. With vegetable tanning, a quality artisanal calf or alligator strap typically lasts 5-7 years of moderate daily use. The leather develops a natural patina that enhances its aesthetics over time. Exposure to excessive moisture (frequent diving) shortens lifespan. FKM rubber straps, conversely, guarantee 10-15 years of complete resistance, ideal for intensive marine use.