I thought an update on how the Citizen bulls evolved might be nice. The original was made in 1973 and at 36mm was considered to be the smallest chronograph (with a fly back second measuring hand) of any production watch. Then in 2012 Citizen released an Eco version of the original bull. A limited version of 500 most which never left Japan. Its case measures at 40 mm and came with a matching titanium bracelet which featured micro adjusting while on the wrist. Now in 2018 Citizen on its 100th anniversary came out with the Promaster, "Tsumo Chrono" (which means horned chronograph in Japanese) and measures at a whopping 44.5 mm. You see a trend here? I thought I would show you the differences in size with a few of my bulls in my collection. Oh, I should mention that in the 1970s Citizen also featured a more angular octagon cased bull which wasn't popular back then, but seems to be more so today due to it's rarity.