Mixed martial artist Conor McGregor spotted wearing a Jacob & Co

Conor McGregor was photographed in the hours before a scheduled UFC bout wearing what is arguably the most ostentatious timepiece available from any major atelier: the Jacob & Co Astronomia Tourbillon in 18K rose gold, reference AT800.40.BD.BD.A. The sighting was characteristically on-brand for the Irish fighter, who has long used pre-fight media windows as an opportunity to signal status through accessories.

The Astronomia Tourbillon ref. AT800.40.BD.BD.A is a limited edition of just 18 pieces. Its movement — the manually wound Jacob & Co Calibre JCAM09 — is housed beneath a sapphire crystal dome that allows an unobstructed 360-degree view of the four-arm rotating architecture. Every 60 seconds, the entire carousel completes one revolution, meaning the watch displays time through motion rather than through conventional hands. The flying tourbillon rotates on its own axis every 60 seconds, the Jacob-cut diamond spins at a different rate to catch ambient light, and the time itself is read from a subdial that counter-rotates to remain upright throughout the full sweep. The movement operates at 3 Hz with a 60-hour power reserve.

What separates this reference from the standard Astronomia Tourbillon is the stone count and setting methodology. The 288 Jacob-cut diamonds on the dial structure are proprietary to the brand — each stone is cut to a patented 288-facet geometry that dramatically increases internal reflection compared with a standard brilliant cut. The 80 baguette diamonds set into the lugs are invisibly set, meaning no metal prong or bezel is visible between stones, a technique that demands exceptional precision from the setter and adds significant labour cost to an already stratospheric price point.

From a collector standpoint, the Astronomia Tourbillon occupies a niche that few houses compete in directly: haute horlogerie movement complexity combined with high jewellery stone work, at a production volume so low that secondary market availability is essentially circumstantial. The 18-piece limitation ensures that each unit retains individual significance rather than becoming a catalogue piece.

McGregor has built one of the most documented personal watch collections in sport, with a consistent preference for Jacob & Co across multiple references. UK list price for this reference is positioned at approximately £1,000,000, placing it firmly in a tier occupied by grand complications from Patek Philippe and Richard Mille's most complex pieces. Grey-market pricing, where transactions occur at all, tends to track closely with list given the scarcity of supply.