Rolex Week Calendar New. The original model 3255 calibre, 40 mm diameter men's watch, shows a superb precision timepiece level. This self-winding mechanical movement is the pinnacle of watchmaking. This 14-issue calibre is excellent in precision, power reserve, shockproof, anti-magnetic, convenience and reliability. Calendar bay window blue film, sapphire mirror, 316l steel. Waterproof 200 meters.