Calibre Calibre Type: Automatic - Powered By The Movement Of The Wearer Calibre Function: Analogue - 3 Hands Accuracy: +25 -15 seconds a day at normal temperature range (5°C and 35°C) Power Reserve/Battery Life: Approx. 70 Hours Power Reserve Battery: N/A Calibre Number: 6R31 Display: Analogue Case Water Resistance: 100 Metres Case Material: Stainless Steel Case Size (Thickness): 12.3mm Case Size (Diameter): 40.5mm Case Color: Silver Band/Bracelet: Strap - Leather (Cordovan) Band Color: Black Glass Material: Dual-curved sapphire crystal Crown: Pull Out Rotating Bezel: N/A Dial Color: Light Blue Arita Porcelain Layout Hand Indicators: Hour, Minute, Seconds Calendar Indicators: N/A Lumibrite: N/A Dial Markers: Roman Numerals Features Hand Winding Capability: Yes See-through case back: Yes