Driving system Mechanical Caliber F8B61 Average daily difference +15 seconds to -5 seconds (static accuracy)* Driving time 70 hours or more Case material Stainless steel (SUS316L) Glass material (front) Double-sided sapphire crystal (sar coating) Glass Material (Back) Sapphire crystal Luminous Light Band Material Stainless Steel (SUS316L) Band width 20mm Wrist length 140mm~200mm Inside clasp push button tri-fold type Weight 142g Diameter 46.5mm Width diameter 39.0mm Thickness 10.8mm Water Resistance 5 atmospheres Other Features Water resistant to 5 atmospheres, power reserve indicator, second hand stopper, 22 jewels, see-through back, genuine alligator leather replacement band