Over the last decade, two indelible forms have often marked MB&F’s Horological Machines: the distinctive angular form and optical prism displays of the revisited 1970s Amida watch, which first manifested in the Horological Machine No. 5 HM5 we reviewed here and then on the HMX we featured here; and the now signature “battle-axe” winding rotor, which took center stage on top of the Horological Machine No. 3 HM3, MB&F's most popular model to date.