Build a custom open-work watch around the Seiko NH70A skeleton automatic movement. Manufactured by Seiko Instruments (SII) / Time Module (TMI), this 24-jewel caliber combines exposed mechanical architecture with hacking and hand-winding functionality.

Movement Specifications

• SKU: WCNH70
• Caliber: Seiko NH70A
• Movement Type: Automatic; hand-windable
• Jewels: 24
• Power Reserve: Approximately 41 hours
• Frequency: 21,600 vibrations per hour / 3 Hz
• Accuracy: Approximately -20 to +40 seconds per day
• Outer Diameter: 27.40mm
• Height: 5.32mm
• Winding Direction: Bidirectional, Magic Lever system
• Functions: Hours, minutes, central seconds and hacking
• Manufacturer: Seiko Instruments (SII) / Time Module (TMI)

Included

Movement with mounting screws, tabs, dial spacer and crown stem.

Confirm case, dial and hand compatibility before assembly. Professional installation is recommended.