I’m quite exited to review another bumper automatic as these are somewhat limited to a certain timeframe in horological history; spanning from the 1930’s up to 1960. This time we will look at Zeniths rather late entry to the automatic watch market; The calibre 133. Introduced in 1951 bumpers were starting to look a little dated, specially next to the likes of Eterna Matics and Longines fully oscillating bi directional winding movements. Ironically it also happened to be the same year Rolex’s stubborn fully oscillating weight patent from 1931 expired. That aside it could be argued it’s one of the smoothest bumpers ever made, with innovative features like the direct driven sweep seconds wheel and a very smooth autowinder mechanism.