Hamilton has built upon this concept with the American Classic Chrono-Matic 50 Auto Chrono Limited Edition, a variant that adopts a racing-inspired blue and orange colour scheme. This new release is produced in a limited batch of 150 pieces.

At its core, the new model (reference H51606640) follows the design principles of the 2019 version. The stainless steel case measures 48.5 mm in diameter and 16.05 mm in thickness, and its sloped upper profile is reminiscent of vintage sports watches. Rather than extending from the sides, the 22 mm lugs are recessed into the underside of the case, resulting in a lug-to-lug measurement of 51.5 mm—a size that appears compact despite the sizeable case diameter.

The top is protected by a box-shaped sapphire crystal, while the caseback is engraved with the limited-edition number (out of 150), though no images of this engraving have been provided. The watch offers a water resistance of 100 metres, which meets the demands of most collectors.

The design extends to the controls: the case sides partially enclose two crowns and three pushers that manage the movement and the internal rotating bezel. On the right-hand side, a winding crown is flanked by two pushers dedicated to the chronograph function. On the opposite side, a secondary crown at the 8 o’clock position rotates the internal countdown bezel, and an additional pusher at 10 o’clock serves to correct the date display.

The pushers are deliberately colour-coordinated; the chronograph pushers are finished in bright orange, contrasting with the black date-corrector button, a detail that harmonises with the overall racing theme.

The dial retains the layout first seen in the 2019 model but now features a dark blue surface with white and orange accents. A speedometer-inspired register at 9 o’clock displays the running seconds, while a 30-minute totaliser is positioned at 3 o’clock. A circular date window sits at the 6 o’clock position, revealing a white calendar disc. Luminescent hands and applied hour markers ensure legibility, and two additional scales enhance functionality. A tachymeter scale is set directly under the crystal, and between this and the main dial lies a rotating internal bezel. This bezel, featuring an orange 60-minute countdown scale with a split white and blue finish, enables the watch to function as either a count-up or count-down chronograph.

The new limited edition is powered by Hamilton’s Calibre H-31 automatic chronograph movement—a two-register variant based on the Valjoux 7753 architecture. Maintaining an operating frequency of 28,800vph (4 Hz), this movement offers a 60-hour power reserve and features an open-worked rotor displaying Hamilton’s H-shaped logo. Complementing the modern internals, the watch comes with a blue calfskin leather strap. The strap’s perforated design reveals an orange internal lining, reinforcing the watch’s racing-inspired aesthetic.

Hamilton’s history is marked by significant milestones, including its early work on automatic chronographs. The vintage Count-Down GMT Chrono-Matic from the 1970s was powered by the historic Calibre 11—one of the world’s first self-winding chronograph movements. Although the new Chrono-Matic 50 has removed the GMT complication, it retains the countdown feature and the distinctive case design, paying homage to the pioneering era of sports watches. The model’s production in a limited run of just 150 units and its unchanged retail price of USD 2,545 also align it with Hamilton’s approach to offering distinctive, collectible pieces.