Exterior Exterior: Stainless steel Case back: Screw case back Glass Material: Sapphire crystal Glass Coating: Anti-reflective coating on inner surface LumiBrite: LumiBrite on hands, indexes and bezel Case size: Diameter 44.2mm Lug-to-lug 51.0mm Thickness 14.0mm Band width: 22mm Clasp type: Three-fold clasp with secure lock & push button release, solid & slide adjuster The perimeter of Band: 195mm Movement Caliber no.: 9R65 Instructions Movement Type: Spring Drive Power reserve: Approx. 72 hours(3 days) Accuracy: ±15 seconds per month (±1 second per day) Functions Magnetic resistance: 4,800 A/m Weight: 201 g Other details / Features: Unidirectional rotating bezel Screw-down crown Three-fold clasp with secure lock 30 jewels Power reserve indicator