Seiko SSA425 Presage Stainless Steel Watch

Seiko SSA425 Presage Open Heart

The Presage line built its reputation on dial craft, and the SSA425 takes a different approach—showing off what’s inside rather than hiding it. The open-heart cutout at 9 o’clock reveals the balance wheel in motion, a reminder that there’s actual mechanical engineering under the dress watch exterior.

The Open Heart Design

That aperture at 9 o’clock isn’t just decoration. Watching the balance wheel oscillate at 21,600 beats per hour is genuinely mesmerizing. The black dial provides contrast, and the 24-hour subdial at 3 o’clock balances the visual weight. Beige LumiBrite on the hands and indices adds vintage warmth.

Dress Watch Dimensions

At 40.8mm with a 47mm lug-to-lug, the SSA425 wears like a proper dress watch—present but not overwhelming. The 12.8mm thickness keeps it comfortable under a cuff. Box-shaped Hardlex crystal adds depth to the dial view.

The 4R39 Movement

The 4R39 is Seiko’s open-heart caliber—24 jewels, 41-hour power reserve, hacking and hand-winding. It’s the same reliable base as the 4R35/4R36 family, configured for the visual display. The see-through caseback shows the decorated rotor.

What You Get

The SSA425 is a dress watch that actually shows something interesting. The open heart gives it conversation-starter status without the price premium of skeleton watches. Presage quality, mechanical interest, reasonable price.