Calibre No. H820 Maximum run time from full charge (Normal Use Condition) Approximately 6 months Movement Eco-Drive Signal Reception Global Radio-Controlled Strap Stainless Steel Water Resistant Water Resistant to 10 bar Thickness 11.8mm Case Size 44.3mm Case Stainless Steel Surface Processing IP Black Specification 24hrs, Date and Day Display Dual Time Alarm Eco-Drive (recharged by any light source, no need for regular battery replacement) Insufficient Charge Warning Function Overcharge Prevention Function Perpetual Calendar Global Radio-Controlled 26 World Cities Time .