Old world inspiration meets new world technology in this retrograde perpetual calendar alarm unlike any other. This stainless steel watch features dual time, month-day-date, 12/24 hour time, non-reflective crystal, a 39mm screw-back case, water-resistance to 100 meters, and a leather strap with push button deployment clasp. Featuring our Eco-Drive technology – powered by light, any light. Never needs a battery. Caliber number E870.