Bart and Tim Grönefeld, known as the Horological Brothers, have over the past decade, earned a stellar reputation for crafting innovative timepieces with a mission to "build elegant timepieces with surprising mechanisms". Coming from a watchmaking lineage that began in 1912 with their grandfather Johan Grönefeld, the brothers are deeply passionate about creating exceptional complications designed to be cherished for generations.

Released in 2010, the One Hertz was the world’s first serially produced watch featuring independent deadbeat seconds. While the deadbeat seconds complication is not new to horology, the Grönefeld brothers introduced a groundbreaking secondary gear train to power it. This unique system allows the seconds to be driven by one independent mainspring barrel, while the hours and minutes are powered by a separate mainspring, ensuring precision and efficiency. Ingeniously, the brothers designed a system where the crown does not need to be pulled out; instead, pressing the crown toggles between winding and setting modes. The movement of the One Hertz is equally remarkable, with bridges and plates crafted from steel rather than the more commonly used brass.

The present One Hertz 1912 in stainless steel is one of the rarest iterations of the model, with only 12 examples ever produced. Adding to its appeal, this particular piece was acquired directly from the Grönefeld brothers, as confirmed by the Certificate of Authenticity, making it a truly exceptional collector’s item.