The Seagull ST3601 is a highly respected, manual-wind mechanical watch movement manufactured by the Tianjin Seagull Watch Company. It is a faithful clone of the classic Swiss Unitas (ETA/Unitas) 6497-1, a legendary pocket watch movement widely used in large-case wristwatches.

The ST3601 is a favorite among watch enthusiasts, modders, and independent watchmakers for several reasons:

• Reliability: Based on a proven, robust design that has been in production for decades.

• Large Size: Its 16.5''' (36.6mm) diameter makes it easy to work on and gives it a commanding presence in large pilot, diving, or "skeleton" style watches.

• Serviceability: Parts are abundant and the design is simple, making it easy to maintain and regulate.

• Affordability: It offers exceptional value, providing a high-beat, accurate mechanical movement at a very low cost.

• Modding Potential: Its large size and classic construction make it a perfect base for decorative finishing, engraving, or skeletonization.

The "ST3601" designation is specific to Seagull and typically indicates the base movement with a standard hour/minute/second configuration. It is often found running at a modern 21,600 BPH, offering a smoother sweep than its historical Swiss counterpart.

Seagull ST3601 Specification List

This spec list covers the standard, unmodified version of the movement.

Note: There are slight variations of this movement (e.g., ST3601K with a different finish), but the specifications above represent the core features of the standard ST3601.