Rare Zenith Defy ref. A3651, the "Safe of Time" (so defined at the time), is an automatic watch produced in the 1970s, with impressive strength and impermeability for the time, so much so that it is declared waterproof up to 300m. It has a total steel case with screw back, a screw ring, a screw-down crown and high-strength mineral glass. Dimensions (37mm) and weight are extraordinary for the time. VERY RARE BLU DIAL IN TOP CONDITION. This specimen mounts the valuable manufacturing movement Zenith cal. 2562PC, mechanical with automatic winding, which was the first Zenith automatic movement with 28,800 alternations per minute, which guarantees greater precision. Perfectly working , just been complete serviced 07-2019 it keeps time well, the recharge is efficient and the calendar is properly triggered. Original crown .I would like to highlight the original luminous dial. There is some lumina missing in the hour hand. Zenith original stainless steel band Gay Freres clasp signed 4-70 total length cm 16.3. COMPLETE ORIGINAL BOX AND WARRANTY PAPERS BOOKLET BLANK.