This is a very cool and wearable 5513 No Date Sub. One of the first meter first dials produced. For those new to vintage Rolex collecting, this type of dial is called the Meters First Dial because in the printed depth rating, the depth in meters precedes the depth in feet. The change from the gilt gloss dialed 5513 to the meters first matte dialed 5513 started around the 1.6 mil serial range or 1966. The majority of the cases stamped with a 1.7 serial number were produced in 1968, and by then the meters first matte dial was in full production. However the period from late 1969 to early 1970, consistent with the 2.2 mil serial range, represents an overlap in which both meters first and feet first matte 5513 dials can be found. I have read that perhaps the reason for the transition from meters first to feet first was an attempt to increase sales in the US market, a country that had not at the time and still has not widely adopted the metric system. - Reference 5513 - 40mm steel case -seriennr 1.2 mill.1965-66 - Matt dial with amazing tritium Patina - beatiful bezel insert - Oyster bracelet ref 93150 with 580 endlinks - Fully serviced by our watchmaker - 2 Year mechanical warranty - Includes a Casa Pieper watch pouch - Free worldwide Fedex Priority shipping