The Perpetual Calendar can be adjusted forward and backward over a single crown, H/M/s/D/DD/M/Y, 2nd time zone on main dial with patented quickset. Permanent home time on 3rd hand. Big Date in double window. Ref. Nr. 320-90/62 Diameter 42 x 42 mm Case 18 ct white gold Dial Slate dial Movement UN-32 Power-reserve Approx. 45 hours Winding Self-winding Water-resistant 50 meters Crystal Sapphire crystals Strap Leather strap Buckle type Folding clasp