The Grönefeld Principia is housed in the company’s 1941 case. Named after the year their father Sjef was born, the 1941 case exudes grace from every angle. This model has a stainless steel case fitted with a sapphire crystal caseback. The clear exhibition back confers a spectacular view of the extensively hand-finished movement with the brand's well-known stainless steel bridges and a 22-karat solid gold oscillating weight.

Just as the award-winning 1941 Remontoire, Bart and Tim Grönefeld want the 1941 Principia again to appeal to the most discerning watch collectors. It was therefore imperative that the movement was befitting of such a timepiece. The stainless-steel bridges replicate the facades of the Dutch houses, termed ‘bell gables,’ once again, referencing the homeland of the Horological Brothers. The bridges are hand-beveled, evincing a brilliant gleam, and have their jewels set in gold chatons.

The 1941 Principia Automatic is fitted with a 22-karat solid rose gold monobloc rotor. The eye-catching oscillating weight is extensively decorated by hand and turns on a ceramic ball bearing, preventing wear and eliminating the need for lubrication. This movement includes a balance wheel with white gold timing screws and is equipped with a reliable free-sprung hairspring. Each movement is finished and assembled by hand. A gold plate, engraved with an individual number, is applied to the movement to emphasize the manual labor involved.