The Hamilton Jazzmaster Open Heart Auto 40mm (H32675140) is a dress watch with a partly openworked dial that reveals the balance wheel. Hamilton’s official page lists a 40 mm stainless steel case, 11.05 mm thick, with 20 mm lug width, a sapphire crystal with anti-reflective coating, an open case back, a blue dial and 50 m (5 bar) water resistance. The H-10 automatic caliber provides an 80-hour power reserve with a Nivachron balance spring, and the watch is on a stainless steel bracelet with a folding clasp. Hamilton lists it at $1,295 in the US.

Owners and buyers praise the elegant design, the open-heart cutouts and the finishing. A long-term owner on Dialicious reports no breakdowns in over ten years, calls the build robust and the 40 mm size comfortable, and the watch averages 4.0 out of 5 there. The recurring complaint is the legibility of silver hands against the silver movement underneath, and one buyer notes the dark blue dial shifts with the viewing angle.

The Jazzmaster Open Heart Auto 40mm is part of Hamilton’s current collection and is listed on the official store.