Grand Seiko Heritage
External
Exterior: Stainless steel Case back: Stainless steel and sapphire glass
Back cover specifications: Transparent screw back cover
Mirror material: Hyperbolic sapphire
Coating: Internal anti-reflective coating
Case size: Width 40.0mm Height 46.2mm Thickness 12.5mm
Band width: 19mm
Nakadome: One push three fold method
Movement
Movement: 9R65 Description
Drive system: Spring drive automatic winding (with manual winding)
Running time: Lasts about 72 hours (about 3 days) at maximum winding
Accuracy: Average monthly difference ±15 seconds (equivalent to daily difference ±1 second)