Seiko Presage SPB527 – Classic Open Heart Automatic Watch

The Seiko Presage SPB527 is an elegant mechanical timepiece from Seiko’s Classic Series that beautifully blends Japanese heritage design with modern watchmaking excellence. Featuring a rich Ai-iro indigo blue open-heart dial inspired by traditional Japan Blue, this automatic watch showcases textured details and a dynamic sunburst finish that plays with light from every angle. Powered by Seiko’s automatic Caliber 6R5J movement with a 72-hour power reserve and practical complications like a 24-hour hand and stop-second function, the SPB527 is ideal for the enthusiast seeking both style and substance in a versatile 40.2 mm package.

Specifications
Model: SPB527 / SPB527J1
Collection: Seiko Presage Classic Series
Movement: Automatic with manual winding — Caliber 6R5J (~72-hour power reserve)
Accuracy: +25 to −15 seconds per day
Jewels: 24
Functions:
- 24-hour hand
- Stop-second hand function
Case Material: Stainless steel with super-hard coating
Case Size: 40.2 mm diameter × 13.0 mm thickness
Lug-to-Lug: ~46.0 mm
Crystal: Dual-curved sapphire crystal with anti-reflective coating on inner surface
Bracelet: Stainless steel with deployment clasp and push-button release
Lug Width: 20 mm
Water Resistance: 10 bar / 100 m
Magnetic Resistance: 4,800 A/m
Case Back: Screw-down see-through case back
Dial: Indigo blue sunburst “Ai-iro” with open-heart display