http://watchguy.co.uk/guest-post-lemania-273000-the-moon-watch-caliber-321s-lesser-known-cousins/ The story most have read in one form or the other is how Omega started using the caliber 321, at the time known as 27CHRO C12, for their chronographs in the mid 1940s. The development of the 27CHRO C12 movement was conducted by Albert Piguet from Lemania. There are a multitude of explanations on what Omegas role in the development was. The story, as documented by Omega themselves in their reference book “Omega Saga”, is as follows: After the great depression in the late 1920´s and early 1930´s the Swiss watch industry was going through their worst crisis prior to the Quartz onslaught of the 1970´s. So in 1930 Omega and Tissot joined together under a common umbrella called SSIH (Société Suisse pour l’Industrie Horlogère). Lemania was at the time known as a relatively small volume, but high quality, manufacturer of complicated watches like chronographs. These where both wristwatches as is our focus here, but also various timekeepers for military, aviation and automotive purposes. As times grew even harsher, Lemania decided to join Omega and Tissot in SSHI in 1932. The deal was that Lemania would get fresh capital and access to a wider and stronger sales organisation, and the other brands within SSHI would get access to the technically advanced movements made by Lemania. Mr. Marius Meylan, CEO of Lemania, was granted a seat at the board of SSHI at the time of merger, and Omega suddenly had access to top grade chronographs, allowing them to become the official supplier to the 1932 Los Angeles Olympics. Omega has been the official Olympic timekeepers ever since! Within SSHI at this time Omega was the luxury brand, Tissot the budget alternative and Lemania the technically advanced “tool watch” supplier. This story lead us back to the development of the caliber 321: Lemania started the manufacturing of the CH27 as early as in 1941. In 1942 the first Omega version was shown as the 27CHRO (later named 320 and 321). Omega themselves states the movements as having been designed and built by Lemania so little room for discussion here. The 320/321/CH27 was manufactured for the next 25+ years. Outside of SSHI various versions of the chronograph movements was used by other companies. Even Patek Philippe, Audmars Piguet and others have used the Lemania CH27 as basis for some of their finest chronograph movements. Breguet has a version for sale with a Tourbillion escapement as well for those of you with really deep pockets.