This MB&F 18K Rose Gold Horological Machine No.1 Tourbillon HM1 is rated 9.7 out of 10. Horological Machine No.1 was an innovative and totally original timepiece. It was the world’s first movement with four barrels connected in both parallel and series, as well as the first wristwatch movement to have energy transmitted to the regulating system from two sources simultaneously. HM1’s three-dimensional case and sophisticated multi-strata of the dial both captivate the eye and challenge the mind. Within that structure beats a movement like no other: 376 parts, 81 functional jewels, 4 mainspring barrels, 7-day power reserve and an elevated central tourbillon. Watch only.