Jazzmaster Open Heart Auto 42mm Brown - Leather Ref. H32705501

Since its founding in 1892, Hamilton has established itself as a name synonymous with solid performance, exceptional build quality, and incredible value. Although the brand is now based in Bienne, Switzerland, its American heritage remains a vital part of its DNA, blending a proud, adventurous spirit with Swiss horological precision. The Jazzmaster collection, in particular, represents the more refined side of this lineage, offering a range of contemporary designs that draw on decades of expertise. While the Open Heart was once primarily associated with smaller, more delicate proportions, Hamilton has brought the concept back to the forefront with a bold 42mm execution. The latest Jazzmaster Open Heart Auto 42 in Brown is a perfect example of this upscale evolution, combining a sophisticated aesthetic with a high-performance Swiss movement that feels right at home on a modern wrist.

Hamilton Jazzmaster Open Heart Auto 42mm Brown - Leather Ref. H32705501

Encased in 316L stainless steel, the Jazzmaster Open Heart Auto Brown features a unique case architecture that expertly plays with light. The tops of the curvy lugs are finished with a fine satin brushing, providing a soft, matte contrast to the high-polished bezel and case sides. These mirror-polished surfaces catch the light from every angle, accentuating the sleek, fluid lines of the design. At 42mm in diameter, the watch strikes a perfect balance; it offers a commanding presence on the wrist without ever feeling bulky or overbearing. This is further enhanced by a svelte 11.4mm thickness and a 49.7mm lug-to-lug distance, dimensions that ensure it sits comfortably and securely across the arm. It's the ideal middle ground for those who want a timepiece with a contemporary scale that remains sophisticated and wearable.

The main attraction of the watch speaks a thousand words with the fantastic semi-skeletonized smoky champagne brown dial. The dial flaunts an impressive pattern that radiates out from the middle, together with a sunburst effect that glistens with the light; definitely a dial that will not fail to impress. Various cut-outs on the dial reveal a glimpse of the meticulously finished intricate mechanical parts that are powering the watch, allowing for a pleasurable experience when viewing the time as the balance, escapement and barrel interact with each other. Above all, this design establishes a sophisticated style that is simply phenomenal.

Semi-skeletonized dial to view the open work

At the heart of the Jazzmaster lies the Hamilton caliber H-10 automatic movement, which is a modified 25 jewel ETA day/date movement. The movement's main highlights include the boosted 80-hour power reserve achieved by lowering the 4 Hz beat rate of 28,800 beats per hour to 3 Hz (21,600 beats per hour). The lowered beat rate also translates to a more robust movement due to the lesser friction produced between the parts over time. At the back of the watch, the movement is viewable through the see-through exhibition case back, featuring a custom decorated rotor with the Hamilton logo engraved. The case back is screwed in to attain a water resistance of 5 bar (50 meters).

Paired with the beautiful case, the 22mm vintage brown leather strap pleasingly compliments the piece's overall look with a light and gentle tone. Neat rows of stitchings can be seen running down the strap on each side.

Unique "horn-shaped" lugs

As expected from Hamilton, the Jazzmaster Open Heart Auto Brown is a masterfully executed Swiss-made timepiece that brings plenty to the table—from its gorgeous semi-skeletonised dial to a contemporary movement boasting an impressive 80-hour power reserve. Upscaled to 42mm, the watch commands a more significant presence on the wrist, providing a larger stage for the intricate mechanical details to truly shine. It is a refined choice for the collector who doesn't just want to tell time, but who genuinely cherishes the artistry and internal pulse of a mechanical heart.

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