Caliber No. E031 Movement Eco-Drive Strap Synthetic leather ( Apple leather ) Water Resistant Water Resistant 50m Thickness 8.3mm Case Size 29.5mm Case Stainless Steel Glass Sapphire Glass Specification Diamond: 1pc lab-grown diamond Eco-Drive (recharged by any light source, no need to change battery) Insufficient Charge Warning Function Mother of Pearl Dial Overcharge Prevention Function