Continuing with the electric theme, today’s watch is a rare Officially Certified Chronometer version of the electro-mechanical X8 line. The 0820 movement runs at 21,600 beats per hour, has 19 jewels and mine is uniquely numbered X00294. The case is a very unusual shape, and I think it is unique this model. Mine was made in August 1970:
More on this one here: https://sweep-hand.org/2013/04/19/this-weeks-featured-watch-49-the-x8-cosmotron-chronometer/ (NB I refer to this one and the titanium cased X8 as the only two chronometer grade X8’s – there was in fact one more model, not (yet anyway) in my collection.