Arsa Oversize Steel Chronograph 1940sThe step case hermetique chronoThis large 38mm vintage steel chronograph is in stunning condition with the original factory lines and even the purple lacquer on the caseback. These watches are known as step case, because of the shape of the case; how it flows between the case edge and the crystal, with a noticeable ridge or step. The movement and crystal are actually fitted to the caseback, in one unit that sits within the mid case. These were known