Glass material: Sapphire glass *Anti-reflective coating on the inside Water resistance: 10 ATM Calendar function: Yes Other features: Surface treatment: Black IP (bezel) Stopwatch: With 1-second, 30-minute counters and split Battery charge warning function Battery indicator display Operating time: Operating time from full charge until the hands stop moving: Approximately 5 months Accuracy: Average monthly difference: ±20 seconds Date display Weight: 61g Other: ●Band: Synthetic leather band ●Length: 175-215mm/25.0mm ●Case size: 50.1×44.5×13.8mm ●Weight: 61g ●10 ATM water resistance ●Stopwatch (with 1-second, 30-minute counters and split) ●Battery charge warning function ●Battery indicator display ●Date display ●Operating time from full charge until the hands stop moving: Approximately 5 months