Grand Seiko · Spring Drive

Strap for Spring Drive Platinum / Kirazuri / U.S. Limited Edition

Takes 20 mm straps. Verified lug width, the straps that fit this model, and answers to the most common questions.

Lug width20 mm
Case diameter40 mm
ReferenceSBGA385
FamilySpring Drive
MovementGrand Seiko caliber 9R15 hours, minutes, seconds | date | power reserve indicator
Year2018 - 2018
CasePlatinum

Spring bar

Swiss Standard universal spring bars

The right category for this model · 316L steel, all lug widths 13–26 mm

Straps for the Spring Drive SBGA385

Selected for the 20 mm lug width · workshop selection

All 20 mm straps →

The Spring Drive SBGA385, seen from the bench

The Grand Seiko Spring Drive SBGA385 is a platinum sport watch with a 40 mm case and 20 mm lug width. It features the Grand Seiko caliber 9R15 movement, a hybrid mechanism combining mechanical and quartz precision with ±10 seconds per month accuracy. The distinctive Snowflake dial reflects light according to precise geometries, evoking ice crystals from Shinshu, the birthplace of Grand Seiko. This U.S. Limited Edition timepiece represents haute horlogerie craftsmanship and daily wearability combined.

Frequently asked questions

What is the lug width of the Grand Seiko Spring Drive SBGA385?

The lug width of the SBGA385 is 20 millimetres, measured from inside point to inside point of the case lugs. This measurement is essential for selecting compatible straps without error. A strap of different dimensions would either leave gaps in the lugs or fail to insert into the case entirely.

What is the best material for an aftermarket strap on this model?

For the SBGA385 in platinum, the finest aftermarket strap is grey or black alligator (which dialogues with the Snowflake dial) or vegetable-tanned calf leather (which ages by developing a rich patina). Shell Cordovan is excellent for those who appreciate the warmth of deep burgundy, while pure cotton-nylon NATO in grey offers daily practicality whilst maintaining elegance.

How do I change the strap on a Grand Seiko Spring Drive SBGA385?

To change the strap, remove the original lugs using a dedicated strap removal tool or small screwdriver. Insert the left lug of the new strap into the case, then the right lug. Ensure the strap is the correct width (20mm) and that the deployant buckle is positioned so the case remains aligned and protected. If uncertain, consult a professional horologist.

Can I use an aftermarket strap on my SBGA385?

Yes, absolutely. The SBGA385 is compatible with any quality 20mm strap, provided it is crafted from noble materials such as alligator, Shell Cordovan, vegetable-tanned calf leather, or pure NATO fabric. We recommend selecting straps with a deployant buckle or clasp matching the quality value of the platinum case.

How long does a leather strap last on a daily-worn watch?

A fine leather strap (alligator, Shell Cordovan, vegetable-tanned calf) typically lasts 5-8 years with daily wear, developing a fascinating patina over time. Durability depends on exposure to perspiration, water, and climatic variation. Pure NATO straps last 10+ years. We recommend rotating straps and storing them in a dry environment when not in use.

The next step

The right strap isn't chosen. It is built, together.

From the atelier appointment to delivery, every step is made for those who know that things done well take time. Rare leathers, one piece at a time, eighteen months of warranty.

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Casati Milano · Via XX Settembre 15, Milan · by appointment only