With the Neomatik model, the Tetra has received two important updates: a larger (33*33mm) case, and an automatic 'neomatik' (caliber DUW 3001) movement. What remained are the perfectly square case, the stepped lugs and the distinct typeface.Reference 422 has a 'tiefblau' blue dial. The 421 was released simultaneously and features a silver dial. With the introduction of the Neomatik 'nachtblau' series, the model was renamed to Tetra Neomatik Nachtblau. We are not sure if the dial color actually changes, although it does appear to be the case judged by pictures.
