The Oris Divers Sixty-Five is among the brand's most iconic and recognised collections, going back to the original from 1965 (hence the name). There are a handful of distinctive and unique variations, such as this faithful reissue of a classic, but most follow the same general design language. The latest Divers Sixty-Five 12H Calibre 400 brings the in-house calibre 400 to the series in a non-limited edition, which is a first. We've already seen the new movement in Aquis divers, so it's great to have in-house Divers Sixty-Five models in regular production.The stainless steel case is 40mm in diameter, which is fairly standard for the series and a perfect contemporary size. The bidirectional rotating bezel has a black aluminium insert that's familiar enough, but it now sports a 12-hour scale for a second time zone. This is another first for a Divers Sixty-Five in addition to the calibre 400. A double-domed sapphire crystal with an interior anti-reflective coating protects the dial, while a sapphire exhibition caseback displays the in-house automatic. The slightly oversized crown screws down and is easy to manipulate, and water-resistance is rated at 100 metres. There are two 20mm strap options – black leather with a steel pin buckle or a three-link steel bracelet with a folding clasp. Ad - Scroll to continue with article The dial continues the monochromatic theme with a matte black finish and applied silver indices with white Super-LumiNova inserts. The silver hour and minute hands have Super-LumiNova inserts as well, along with a lollipop seconds hand. A dial-matching black date window sits at 6 o'clock. I generally prefer Divers Sixty-Five models without the date, but this one is subtle enough to not only blend well but even be preferable. These models have colour to some degree, whether in the case, the dial or the lume, but we have a strictly black and white (and silver) piece here.As mentioned earlier, the in-house calibre 400 automatic runs the show. It replaces the Sellita SW200-1 (calibre 733) and brings several improvements. For starters, it has 24 jewels and beats at 28,800vph, and goes from the Sellita's 38-hour power reserve to 120 hours (5 days). It has more than 30 anti-magnetic components including a silicon escapement and exceeds the ISO 764 anti-magnetic standard. Accuracy is also within COSC specifications. In addition, the watch comes with a 10-year warranty and 10-year service intervals, which is standard for any piece carrying the calibre 400. Functions include central hours, minutes, hacking seconds and date. As seen from the exhibition caseback, it's well finished yet undecorated, focusing on performance and value over additional handwork. The Oris Divers Sixty-Five 12H Calibre 400 retails for CHF 3,100/USD 3,500 with the strap and CHF 3,300/USD 3,700 with the bracelet. Not bad for a historic, in-house Swiss diver with a second time zone bezel. For more information, please visit Oris’ website.