Grand Seiko Heritage 9F Quartz SBGP009G The 9F Quartz Model of the Heritage Collection, which has been developed in pursuit of perfection, has been upgraded with the new 9F85 caliber. Caliber 9F85 has a time difference adjustment function that allows the hour hand to be adjusted without stopping the seconds hand and thus preserving its high precision when the wearer changes time zones. Exterior Exterior: Stainless steel Case back: Screw case back Glass Material: Sapphire crystal Glass Coating: Anti-reflective coating on inner surface Case size: Diameter 40.0mm Lug-to-lug 47.0mm Thickness 10.6mm Band width: 20mm Clasp type: Three-fold clasp with push button release Movement Caliber no.: 9F85 Movement Type: Quartz Accuracy: ±10 seconds per year Functions Water resistance: 10 bar Magnetic resistance: 4,800 A/m Other details / Features: Calendar-linked time difference adjustment function