Seiko Prospex SPB381, SPB383, and SPB385 Specifications - Lug Width & Strap Size

The Seiko SPB381, SPB383, and SPB385 watches have a 20mm lug width and are compatible with 20mm watch straps.

The Seiko SPB381, SPB383, and SPB385 have a case size of 42mm in diameter and 12.9mm thick.

The Seiko SPB381, SPB383, and SPB385 have a lug to lug measurement of 48.6mm.