For the tenth anniversary of their brand, "Horological Brothers" Bart and Tim Grönefeld present a flying Tourbillon in a limited edition of ten pieces. Distinctive feature N°1: the 1941 case, named for the birth year of the two watchmakers' father. Sculpted from platinum, what appears at first glance to be a classic round form alternates convex and concave surfaces. Distinctive feature N°2: a flying tourbillon inside a steel carriage. It sits, as though suspended, within a dial made from silver, beneath which beats an automatic movement that purists will appreciate. As always with the Grönefeld brothers, not a single detail has been overlooked. In addition to the red gold rotor, the exquisite circular-grained, snailed, mirror-polished and frosted finishes of the movement can be admired through the sapphire back. A lesson in horological craftsmanship.