Jazzmaster Open Heart Auto 42mm H32705140

Offering a glimpse of its powerful inner mechanics, the Jazzmaster Open Heart lets precision take center stage with a new 42mm dial. Featuring a captivating midnight blue dial that sparkles, this showstopping timepiece fuses the modernity of urban architecture with the infinity of the cosmos. Showcasing Hamilton's ever-evolving craftsmanship and attention to detail, the dial brings the H-10 automatic movement into the spotlight. With its 80 hour power reserve and Nivachron™ balance spring, the Jazzmaster Open Heart Auto is fitted with an intricate stainless steel bracelet. Discover our collection of dress watches. A three-hand movement with or without a date function and boasting a superior power reserve of 80 hours, the H-10 appears with intricate contrasting snail and pearled patterns for the American Classic models it drives and streamlined surfaces for the pilots’ watches.

Source: Hamilton website, last updated Mar 2026